Rumours surrounding Gareth Bale's Bernabeu career are a constant and several of Europe's top clubs are regularly credited with an interest in the Wales international. However, that interest carries a sell-by date and last season was not the greatest advertisement for Bale's longevity as he approaches his 28th birthday. Injuries restricted Bale to fewer than 2,000 minutes over 27 appearances in 2016-17 and he chipped in just nine goals and three assists -- fewer than Marco Asensio, James Rodriguez and Alvaro Morata, all of whom were used more sparingly by Zinedine Zidane.

Bale's nadir came in April's Clasico when, not for the first time since he arrived in Madrid, he rushed back from injury only to limp off 39 minutes into the game, having aggravated a calf muscle problem that would rule him out for the rest of the season. That particular injury has flared up on several occasions during his time at Real Madrid and contributed to his unavailability for roughly 80 fixtures in four seasons at the Bernabeu, although that total was exacerbated by a serious ankle injury that ruled him out for 17 games last campaign.

Still, the niggling feeling persists that Bale's muscle injuries are verging on chronic and given his reliance on explosive speed, it's unlikely to improve without an adjustment in his playing style. In view of Isco's scintillating late-season form once Zidane shifted him into a more central role, and the Real manager's willingness to operate with either a single striker or two up front in the latter stages of the campaign (particularly in the Champions League), question marks over Bale's long-term viability as an automatic starter are uncomfortable but necessary.

Florentino Perez made a huge investment in Bale in 2013 with a long-term succession for Cristiano Ronaldo in the forefront of his mind. An instant impact was guaranteed in such a game-turning individual but suspicions still linger over his team ethic; the Bernabeu crowd is always quick to jeer every shot into the side netting when a colleague is free in a better position.

That is hardly a singular reaction from Real's home crowd, mind you. Similarly, another player who has laboured under their merciless glare is reportedly considering his future though the likelihood of Cristiano Ronaldo jumping ship recedes over the horizon with every passing day. Perez may have earmarked Bale as Ronaldo's heir but the Real president has since unearthed Marco Asensio, who has perhaps already usurped the Welshman in that regard.

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This summer's transfer market could prove to be record-breaking, as several clubs are intent on strengthening their hands ahead of next season. The Premier League will lead the way and both Manchester clubs have the means to set the wheels of a billion-euro merry-go-round in motion. Jose Mourinho is in the market for at least one marquee forward, possibly two, and Pep Guardiola has been getting some tidy business out of the way early. Liverpool and Arsenal are positioning themselves to be involved in any negotiations for Mbappe -- even if economics will ultimately leave them in the wake of their domestic rivals -- while PSG are keen to flex their financial muscle.

Even if Mbappe remains in Monaco, Dortmund have intimated they will entertain offers for Pierre-Emerick Aubameyang (for a set fee) while Romelu Lukaku, Robert Lewandowski, Paulo Dybala and Eden Hazard are all accessible targets for the biggest spenders; the latter's ankle injury is unlikely to put off any serious suitors.

That leaves Real with a decision to make on Bale. As things stand the Welshman remains an attractive target for a club wishing to make a statement signing. Manchester United and PSG will head the queue if Perez decides to cash in, but the Real president will not have infinite opportunities to recoup the bulk of a then-world-record €101 million fee he splashed out four years ago.

Another season beset by injuries or a slide down the pecking order at the Bernabeu, which is a more considerable possibility now than it was 12 months ago, and Bale's value could seriously plummet. Real are likely to pursue Mbappe if Monaco indicate they are willing to listen to offers and the 18-year-old's arrival would further undermine Bale's status at the club.

Even if that potential move is put off for another year, Perez is unlikely to ignore any indication that doing the same in Bale's case could really hit the club in the wallet.