Senne Lammens' will-he, won't-he move to Manchester United was one of the more intriguing deals on transfer deadline day.

Lammens had been identified as a goalkeeper of interest by United early in the window and although their interest intensified in the final week, it was not until deadline day itself the Premier League club made their move.

By that time, the 23-year-old Royal Antwerp player was on his way to England anyway, making sure he was in the right place 'just in case' an agreement was reached.

The deal was eventually announced at 10pm, five hours after the window closed and long after Aston Villa's World Cup winner Emiliano Martinez had given up on his own dreams of securing a move to Old Trafford, having also been put on red alert by United's renewed interest in him.

Lammens described his £18.1m switch as "a dream come true". He also said he hoped it would be the "beginning of something special".

Three weeks on, we are still waiting to see Lammens play a game. No-one knows whether head coach Ruben Amorim will give him his Premier League debut at Brentford on Saturday, in the home game against Sunderland on 4 October, or make him wait even longer.

Firstly, there is no sense Lammens has done anything wrong.

Sources say the Belgium Under-21 international has impressed in training and the overall view of him is a positive one.

Lammens is described as having a calm presence, as being mature for his age and is taking his new surroundings in his stride. He has already got somewhere to live, so has stepped out of hotel life, which in itself can be disruptive.

This view is backed up by United's number three goalkeeper Tom Heaton in an interview with the Training Ground Guru podcast: "He has a strong personality.

"His goalkeeping fundamentals are very impressive. I said that to him after a couple of days' training. He's been very impressive so far."

Around his signing in preference to Martinez, United sources were keen to stress he had been bought with an eye on the future.

His stats were good. Last season, Lammens made 30 appearances in the Belgian Pro League, keeping seven clean sheets and making 173 saves, which was 20 more than any other goalkeeper in Europe's top-10 leagues, while no player saved more penalties than his four.

Data analysts Opta said Lammens had a save percentage of 77.4% and a passing accuracy of 71.5%. They also said his 'goals prevented' total was 18.4.

"Senne is young and has a big frame," said former Belgium and Tottenham defender Toby Alderweireld. "He'll be a perfect fit in England."

There was uncertainty over whether Lammens, with just a single full season as a number one goalkeeper and 57 senior appearances behind him, would be pitched straight into the United first team in the white-hot atmosphere of a Manchester derby on 14 September.

He wasn't, with Amorim explaining why in his news conference a couple of days earlier.

"He has a lot of potential but we also have to look at the present and we are in a moment that the goalkeeper needs to be really strong and have a lot of experience," he said.

"It is a different league, different country, different ball."

Turkey international Altay Bayindir, who had started six of the previous seven Premier League games and all three this season, retained his place at the Etihad Stadium, a 3-0 defeat, and kept it for the victory over Chelsea on 20 September, when the visitors had just one effort on target, Trevoh Chalobah's 80th-minute header into the corner that gave the keeper no chance.

Although Amorim has said Bayindir and Lammens will compete for the number one spot, few think the former Fenerbahce man, who cost United £4.3m in 2023, is capable of filling the role on a full-time basis.

According to Opta, of the goalkeepers with more than two Premier League appearances this season, Bayindir ranks 16th in terms of save percentage (50%). His mistakes in the home games against Arsenal and Burnley mean he has conceded eight goals this season, more than his expected goals conceded figure of 7.14, putting him 17th in the list and a long way behind the leader in that metric, Fulham's Bernd Leno, who has conceded 2.15 goals fewer than he should.

Bayindir is 17th in terms of passing accuracy and 18th for long pass accuracy.

All of these numbers very much lead towards the theory it is a question of when, not if, Lammens gets his chance.

Yet, having elected to keep his new arrival out of the firing line so far, Amorim has to be careful when choosing the right day as a poor performance could set Lammens back.

The selection issue has been made more tricky by United's elimination from the EFL Cup at League Two Grimsby before Lammens had even arrived.

It means there is no 'soft landing' available in a lesser competition, when the consequences for immediate mistakes in the assimilation period would not be quite so great.

United opted against naming Lammens as an overage player in the Premier League International Cup game at Old Trafford on Wednesday night.

While it would be unusual for someone bedded into the first-team squad to feature in a game primarily for Travis Binnion's Under-21 squad, it would at least have given Lammens a taste of playing under floodlights at the main stadium.

Although the attendance of 1,600 was a fraction of what the first team get, it is not far off the crowd of 6,456 who saw Lammens' last senior game, in the Belgian Pro-League for Royal Antwerp at Charleroi.

So, unless he is made to wait until United begin their FA Cup campaign in January, it now seems Lammens will make his next competitive appearance in the Premier League, when the opposition manager will need little invitation to target a rookie.

Former United goalkeeper Roy Carroll has cautioned against expecting too much too soon.

"He's only 23, please, please give him time and let him grow as a Manchester United goalkeeper," the Northern Irishman told BBC Sport.

"We did it for David de Gea when he came in. He was a very young goalkeeper and a successful one even before he came to Manchester United as well.

"Time is a precious commodity but we need to give it. Every goalkeeper makes mistakes, the key is not to make too many."