Jose Mourinho
Jose Mourinho took John Terry off for the first time in his Chelsea career Getty Images

Chelsea manager Jose Mourinho's motives for substituting captain John Terry during the 3-0 defeat to Manchester City have been questioned after he claimed the half-time switch was tactical. The Blues skipper was replaced for the first time in 177 appearances under Mourinho, being replaced Zurt Zouma for the second half at the Etihad Stadium.

Sergio Aguero's pace terrorised the Premier League champions in the first half forcing, Asmir Begovic into a number of saves before the Argentinian opened the scoring on 31 minutes. Mourinho moved to shore-up his back line with the introduction of Zouma, but it came at the expense of Terry who had never previously been taken off during the Portuguese boss's spells in England.

"I had to decide on John or Cahill because Zouma is the fastest player we have in our defensive line," Mourinho told a post-match press conference, according to the Chelsea official website. "When you are going to play with a high block and you are asking your players to do that, the fastest player has to be on the pitch.

"The point was not to bring John out but to bring Zouma in. I wanted to have my fastest player on the pitch and not on the bench because I knew they would play counter-attack and long balls into Aguero. I knew I wanted my team to be dominant and to play in the opposition half.

"I'm the one that plays John every game, made him captain, brought him back from a difficult situation with other managers. I'm the one who has the right to look at the game and say I want Zouma on the pitch. I was losing 1-0, in minute 35 I was trying to anticipate what I was going to say to the players, and ask the players at half-time, and immediately I had Zouma warming up because it was clear to me he had to play."

But Graeme Souness, a five-time league champion as a player with Liverpool, was not convinced by Mourinho's explanation. The Daily Mail understands Chelsea are preparing a third bid for Everton defender John Stones in the region of £30m ($47m), despite Roberto Martinez insisting the England international is not for sale. The former manager of Southampton, Blackburn Rovers and Newcastle United believes Mourinho has attempted to force the hand of owner Roman Abramovich by the removal of Terry and the late introduction of out-of-favour winger Juan Cuadrado.

"I don't think it was anything to do with Terry's performance," he told Sky Sports. "John Terry is still the best centre-back out there. I think [Mourinho] is trying to force the owner's hand to go and buy John Stones. I think it's a manager making a statement to the owner, saying 'I need more players'. What enhances my argument is the fact Cuadrado came on, who is up for sale. I think the manager wants more players and I think he was emphasising that point today."

One plus point on an otherwise disappointing day for Chelsea was confirmation of the signing of left-back Baba Rahman from Augsberg, after the club started the season with just five recognised defenders following the departure of Filipe Luis. Mourinho is hopeful the Ghana international will be fit to make his debut in the trip to West Bromwich Albion on 23 August. "It's important because he's a left-back and he can compete with Azpilicueta," he said. "At the same time, Azpi can also compete with Ivanovic for the right-back position. This player replaces Filipe Luis in terms of the balance of the squad. Hopefully next week he will be ready."