The January transfer window is open and there's shopping to be done by bargain-hungry Scottish Premiership clubs.

Whether fighting for the title, scrapping for survival or chasing a European dream, each of the top 12 have their eyes on a prize, and players to bring in or ship out.

From freebies to multi-million-pound signings, it could be a frantic month of transfer wheeling and dealing. But which club needs what? BBC Scotland delves in to find out...

Sign a striker

A first home loss to Rangers in nine years has intensified the fans' thirst for renewed strength in key positions. Odsonne Edouard has shouldered the striker burden alone for months and the strain is showing. The 21-year-old returned from injury in early December to play six games in 22 games, culminating in the chastening Old Firm defeat in which he was well below his best.

With Leigh Griffiths and Vakoun Bayo struggling for fitness, and the Ivorian yet to convince he is not an expensive mistake, Celtic badly need fresh firepower and talks are ongoing with Slovan Bratislava over a deal for 25-year-old striker Andraz Sporar. Centre-back is another injury-affected area of weakness, with Cruzeiro defender Fabricio Bruno and Moussa Sissako of PSG among the reported targets. Celtic's title defence could well hinge on their January business.

Keep Morelos

New arrivals are unlikely at Ibrox this month with Steven Gerrard looking to trim his bloated squad, but the exit must be barricaded to prevent the departure of top scorer Alfredo Morelos. Speculation over the Colombian's future continues to swirl amid a glut of goals that totals 28 strikes in 35 appearances this season and 76 in 107 games in his two and a half years at the club.

A goal against Celtic continues to elude the 23-year-old, and his improved disciplinary record has faltered with two reds in his last three matches. But he has set scoring records in the Europa League and never been more vital to Rangers. If Gerrard's side are to halt Celtic's pursuit of nine in a row, they need Morelos front and centre.

New frontman a necessity

Motherwell fans are dreaming of a first European campaign since 2014 as they look down on three quarters of the league from their lofty position of third. Playmaker David Turnbull's long-term injury absence has been offset by productive contributions from new signings Chris Long and Jermain Hylton and 19-year-old James Scott's rise to prominence.

A new striker is required to spearhead the European charge, though, with efforts to extend Devante Cole's six-month loan from Wigan Athletic proving unsuccessful. And there's a hint of uncertainty in the last line of defence, with goalkeepers Mark Gillespie and Trevor Carson both out of contract in summer. Securing one or both on a new deal this month would be a timely boost.

Add flair to midfield

New chairman Dave Cormack has ploughed plenty of money into the club and must open the cheque book again to back Derek McInnes' efforts to reinvigorate a depleted squad. Defence and midfield are the focus, with Greg Leigh and Craig Bryson both sidelined for two months and Zak Vayner's season potentially over following a shoulder injury.

A signing in the mould of Ryan Christie - who began a hugely successful 18-month loan stint in January 2017 - would excite the fans and give the team fresh impetus in their attempts to overtake Motherwell in third. And any interest in 22-goal striker Sam Cosgrove must be rebuffed unless silly money is being offered to prise the 23-year-old away from Pittodrie.

Tie down key men on new deals

A summer exodus - goalkeeper and key defenders - looked to have ripped the heart out of the Lions, but savvy recruitment has kept them roaring. Major surgery is not required in this window with Gary Holt's side sitting fifth in the table. Once again home form has been the bedrock of their success - only Aberdeen and the Old Firm have taken more points on their own patch. And Holt's new-look defence is, along with Rangers, the joint most miserly in the division, with five goals conceded from 10 games.

Aaron Taylor-Sinclair, who joined on a short-term deal in November, was this week rewarded with terms until the end of the season and tying down other first-term stars should be the priority. Defenders Alan Lithgow and Ricki Lamie, plus midfield pair Stevie Lawless and Craig Sibbald, are into the final six months of their contracts, so Livi need to be proactive to prevent another hefty summer rebuild.

Holding out for a hero

Jack Ross this month gets his first chance to put his own stamp on the squad he inherited from Paul Heckingbottom. The Easter Road head coach will have to be creative - he has been told he has to sell before he can buy - and funnel any funds he can free up on adding steel to an imbalanced midfield.

Hibs are overloaded with playmakers and creative types, with the likes of Scott Allan, Stevie Mallan and Martin Boyle giving them plenty of menace going forward. Stopping teams slicing them open has been the problem, though. Melker Hallberg and Vykintas Slivka have been left to do the dirty work, but are more box-to-box players than proper holding midfielders. A no-nonsense midfield anchorman should top Ross' shopping list.

Bolster an impotent attack

Kilmarnock look to finally have some stability, now they desperately need a goalscorer. Despite an iffy record as caretaker - three straight 1-0 losses - Alex Dyer has been put in charge until the end of the season after Killie got cold feet with their Angelo Alessio experiment and sacked the Italian 22 games in. They have slipped from fifth to seventh since Alessio's departure and, with just a five-point lead over second-bottom Hamilton, a relegation fight isn't out of the question unless they improve the joint second most impotent attack in the top flight.

Killie have scored just 17 times in 21 matches and failed to net in their last six. Eamonn Brophy - the spearhead of the side that set club record points totals in the previous two campaigns - is the top marksman on four goals and symptomatic of their struggles. Dyer must reinforce the attack to breathe fresh life into a team whose style has become stagnant.

Plug leaky defence

Eight points clear of bottom spot, and three above the relegation play-off berth, makes it a decent campaign so far back in the top flight for the Highlanders. However, the poorest defensive record in the division shows where their weaknesses lie. County are conceding over two goals per game on average and have shipped six more than the next leakiest team, Hibs. Central defenders Liam Fontaine, Callum Morris and Keith Watson struggle to convince they are good enough for the top level and a quality new recruit would raise standards.

Give Hendry a run

Tommy Wright said "I want the Stevie May of old" when he brought the striker back from Aberdeen amid much fanfare in August. As the window reopens, it's clear the version he's ended up with is new but not improved. May was supposed to cure Saints' scoring problems but has contributed only two goals in 15 appearances and the Perth club have the worst record scoring in the Premiership with 16 goals from 19 games.

Wright, aided by the return from injury of Jason Kerr, has solved his side's defensive issues and a five-game unbeaten run with just one goal conceded has hoisted them from bottom to ninth. But up front remains a pressing concern. If Wright can't bring in a new striker, he must give Callum Hendry a sustained run in the team, with the 22-year-old topping the club's scoring charts with five goals even though his 17 appearances include just three starts.

Strengthen injury-hit defence

The Paisley outfit limped into the winter break with a decimated defence that has been further weakened by loan defender Sean McLoughlin's return to Hull City. The Irishman has played every minute of St Mirren's league season so far and leaves a gaping hole at centre-back, where experienced centre-backs Gary MacKenzie and Kirk Broadfoot have missed the last four and eight weeks respectively. However, Jim Goodwin's men finished the year strongly with just one defeat in five matches to sit a point above the bottom two, and bolstering the backline will be key to their hopes of a third consecutive season in the Premiership.

Add experience to youth

Accies have the youngest average age of starting line-ups in the Premiership this season and that faith in youth has been tested by a barrage of injuries. Their latest great escape act hangs in the balance with five points separating Brian Rice's side from bottom club Hearts. Brian Rice won't be afforded the chance to go on a transfer splurge, but a couple of canny signings plus the return of experienced players from injury could be difference between staying up and dropping down.

Surgery required at both ends of pitch

You get the feeling new manager Daniel Stendel would like to rip it up and start from scratch at the Premiership's bottom club. He'll have to make do with a few additions, though, and centre-half and centre forward are the areas most in need of attention. Stendel's decision to drop Christophe Berra for the final match of 2019 - a 1-1 draw with Aberdeen that yielded the German's first point at the fifth attempt - was an ominous sign for the 34-year-old whose best days are a fading memory.

Stendel's preference of a pressing game and high defensive line means a new centre-back will be sought and there is also a void up front. At 33, Steven Naismith simply can't be relied upon to steer clear of injury for sustained spells. The Scotland striker and Northern Ireland forward Conor Washington have mustered just 19 starts between them for Hearts this season, while fellow forwards Uche Ikpeazu and Steven MacLean have a combined goal haul of four. Such paltry returns make a new striker essential.