LONDON -- Mauricio Pochettino has backtracked on his criticism of Moussa Sissoko, explaining that it has been very difficult for the £30 million signing to "adapt" to Tottenham.

Sissoko has made just five starts since joining from Newcastle United in a deadline-day deal and Pochettino criticised the France midfielder after Saturday's 2-1 defeat at Chelsea -- the second consecutive league game he has been left out of the squad.

"Sissoko needs to work hard and to show in future that he deserves to be on the team," Pochettino said at Stamford Bridge but, speaking on Thursday, the Spurs manager offered an explanation for Sissoko's unconvincing start at White Hart Lane.

The 27-year-old did not feature in preseason for Newcastle and he suffered a suspected concussion on his third appearance for Spurs, at Middlesbrough, before he was suspended for three matches for elbowing Bournemouth's Harry Arter.

"He signed on the last day, Aug. 31, he goes to France for international duty, without pr-season, he came back, got concussion, was suspended three games -- it was very difficult for him to find rhythm, adapt and fit into the team," Pochettino said.

"After two-and-a-half years [at Spurs], all of our players that come with us always struggle to fit and to cope with our pressure for the new. Sure, it's not easy for them and he's 27 and with different habits and it's not easy for him. It's not easy for anybody."

Asked about his criticism of Sissoko, Pochettino said: "It's not because I wasn't happy, he's the same and we believe that it was better to have [Georges-Kevin] Nkoudou or Josh Onomah on the bench rather than him but it was a football position.

"I am happy. His attitude this week was very good, he trained very hard but it's not a big issue for me. All the players need to understand that we are 24 and I am the boss, I am the manager. In my contract it says I have the decision to pick 11 and then seven more to be in the squad and when you have 24... it's always my decision. The decision is a football decision and not another thing."