Is Saul already under threat of being a Chelsea flop?

Saul Niguez, Chelsea

Saul Niguez's deadline day move to Chelsea seemed an obvious one for both parties, as the Blues board looked to back manager Thomas Tuchel with a capable fourth midfielder, while the Spaniard felt a change in scenery could help to revive his career.

The 26-year-old's form had been deteriorating in recent years to the point where, once a vital part of Diego Simeone's Atletico Madrid team, he now found himself occupying a bit-part role.

In fact, such a decline in the career of what looked to be a future Atleti legend meant that the purchase price for his signature dropped from £85m (€100m) to £30m (€35m) - Chelsea's option to buy at the end of the season-long loan.

Yet, the opportunity to work with an already experienced player only now entering the prime of his career was one that caught Tuchel's attention, regardless of his recent struggles.

And, of course, he fitted the need of a rotation option for when key midfielders N'Golo Kante, Jorginho and Mateo Kovacic are either injured or in need of a rest.

Saul's Chelsea debut a sign of things to come?

Admittedly, Tuchel threw Saul in at the deep end in Chelsea's league match with Aston Villa, but nevertheless, his performance was one to forget.

The Spain international was dispossessed three times in the first half, prompting the German boss to haul him off at half-time.

"I had the feeling that he struggled," Tuchel told Sky Sports. "There were some big mistakes, passing mistakes, and he struggled with the intensity. You could see he isn’t fully adapted.

"It's completely my responsibility. I had the feeling he could jump in for us and play at that level. I [then] thought it was maybe better to change him, but it doesn’t change anything [about my plans]."

Since then, an underwhelming display in the EFL Cup, again with Aston Villa, has seen 25-year-old academy graduate Ruben Loftus-Cheek apparently move ahead in the pecking order, as expected outcast Ross Barkley also appears to be doing the same.

Now, Saul is under serious threat of becoming the next in a long list of Chelsea flops, with little time to get to grips with the intensity of the English game and competition from a fan-favourite (Loftus-Cheek) whom every Blues fan would be thrilled to see succeed.

Hence, a positive to the deal, from a Blues point of view, is that should Saul fail to impress, the £30m fee does not have to be taken up and he will simply return to Madrid at the end of the season.

But, given the line of clubs queuing up to sign the formerly world-class midfielder as little as a year ago, the Champions League holders will be bitterly disappointed if they are unable to turn a challenging start to the loan on its head.