Ex-loanee Mateo Kovacic shows Saul how it's done against Aston Villa

It was inevitable that comparisons would be drawn between Mateo Kovacic and Saul Niguez when the latter sealed a deadline day loan move to Chelsea from Atletico Madrid ten days ago.

An underused and under-appreciated midfielder on the white half of the Spanish capital, Kovacic had joined Chelsea on a season-long deal from Real Madrid back in 2018 - making the switch permanent and becoming a first-team regular and quasi-fan favourite in three years at Stamford Bridge, having taken to the Premier League like a duck to water.

Although the Croat is rarely among the goals or assists, his tireless running and tenacious approach to the game have endeared him to the Blues faithful; undoubtedly a successful loan signing following spectacular past failures such as Maniche, Quaresma and, needless to say, Falcao.

Saul had been allowed to leave Atleti despite being seen as a prodigal son at Wanda Metropolitano just a few seasons ago, struggling to nail down a starting place and rediscover the form that underpinned his meteoric rise, and growing weary of being played out of position in an unfamiliar wing-back role.

Considering the parallels, there was understandable excitement when the 26-year-old was handed a starting debut for the visit of Aston Villa on Saturday. Would this be the start of another long and prosperous relationship between Chelsea and another outcast Madrid midfielder?

Well, not on this evidence. As the narrative would have it, former Madrid loanee, usual dark horse and goal-shy unsung hero Kovacic had the game of his life, while new boy Saul endured a near-nightmare start to life in England.

Deployed in a deeper starting position than he is perhaps used to, the Spain international clearly struggled to adjust to the demands of the English top flight, especially when confronted with a relentless, aggressive press from Villa.

Saul ceded possession three times in the first half and lost eight of his nine duels - including all seven on the ground - as he was hounded by John McGinn, Jacob Ramsey and Douglas Luiz. One of his errors very nearly led to a goal, but Ollie Watkins spurned the opportunity.

His poor showing did not go unnoticed; Saul was hooked by Thomas Tuchel at half-time, and Blues' head coach acknowledged the Spaniard's 'big mistakes' in a post-match interview with Sky Sports.

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

Kovacic's man-of-the-match display could not have been more contrasting; following a trademark mazy dribble, the Croatian fired a wonderful, lofted through ball from inside his own half into Romelu Lukaku's feet, setting up the Belgian to cut inside and finish clinically.

Then, four minutes after the break, the 27-year-old had a goal of his own - seizing upon a painfully under-hit back pass from Tyrone Mings before finishing sumptuously from the angle. The strike means the midfielder already has more goals and as many assists as he managed in the entirety of last season.

Of course, there is no way Saul should be written off yet and he needs time, but he'll need to adapt quickly in his limited time to make an impression. You feel most coaches would be more likely to entrust the old guard to get the job done otherwise.

Thankfully Tuchel is a rational man, and he was hasty to add that the half-time substitution doesn't mean anything more. "It's completely my responsibility," he said. "I had the feeling he could jump in for us and play at that level. I thought it was maybe better to change him, but it doesn’t change anything."

Kovacic is proof of what is possible with trust, time and persistence.

His presence at Stamford Bridge can be hugely beneficial for Saul and a reference point for his evolution from a La Liga player into a Premier League one. The new arrival has all the attributes to succeed, but there is clearly some confidence that needs to be restored first.