At £21million, Nemanja Matic was the priciest midfield option Chelsea could have gone for in January – but boss Jose Mourinho says he was worth every penny.

Chelsea have been resurgent since the re-signing of the Serbian holding man from Benfica, and Mourinho has lifted the lid on the thinking that brought him back to Stamford Bridge.

“I gave the club, with the technical director [Michael Emenalo], two or three options,” said Mourinho.

“We talked clearly that the most expensive one was Matic, but at the same time the relation between quality and price and the future, he was better for us. We spoke with the owner and the board.

“Obviously the owner and the board cared a lot about our position in relation with Financial Fair Play, but because we knew we were selling [Kevin] De Bruyne - which was before [Juan] Mata - we could compensate for Matic to come without putting at risk the Fair Play position.

“Between us, the board and the owner, we made a decision to go for him - and after that cam the Mata sale and obviously our numbers in relation to Fair Play went into a very comfortable position.”

Asked what the midfielder adds to the team, Mouronho was immediately clear.

“Stability to our midfield and one more option,” he said.

“His way of playing brings stability into the team. It is difficult [for him] to lose the ball, but at the same time he is not the kind of guy to play any square passes, he can do so and keep possession, but he can see the movement forward, look at the passing into space.

“He is very clean. He recovers a lot of balls in a clean way, he doesn’t make fouls in dangerous positions. I like him a lot because of his stability. He is a very stable player for someone who is still so young, only 25.”

Another thing Matic has delivered is squad depth, though Chelsea may yet rue the fact they cannot call on him in the Champions Leaue this season – him being cup-tied.

“It’s not good for us that he doesn’t play Champions League,” said Mourinho. “But it’s good for us in terms of the Premier League because he can rest and doesn’t have that accumulation of matches.

“Instead of playing against Galatasaray, he didn’t. So when I played Matic and Luiz in a crucial position on the pitch, I had two fresh players because against Galatasaray I played Ramires and Lampard.

“It gives me the possibility to make a little turnover in an area of the pitch where players run miles and get tired.”