Juventus coach Antonio Conte has admitted Roberto Mancini's recent arrival at Champions League opponents Galatasaray has upset his tactical plans for the sides' clash in Turin on Wednesday.
And the Bianconeri coach said key forward Carlos Tevez could miss the match after suffering an ankle injury in the 1-0 derby win over Torino on Sunday.
Mancini, sacked by Manchester City at the end of last season following a shock defeat to Wigan in the final of the FA Cup, signed a three-year contract on Monday to manage the struggling Turkish champions.
While his presence in the Galatasaray dugout has yet to be confirmed, Conte believes Manicini - a former coach of Fiorentina, Lazio and Inter Milan - will bring something extra to Galatasaray's gameplan.
"I'm really happy that Roberto is back in charge of a team, he's one of the best coaches in Europe," Conte told media on Tuesday.
"But I would have preferred to be meeting him a bit later on, we lost all of the tactical reference points we had on Galatasaray."
Galatasaray will hold a press conference later Tuesday, where Mancini is expected to appear.
For both Italian coaches Wednesday's Group B clash is crucial.
Conte's men dominated FC Copenhagen a fortnight ago but left Denmark frustrated following a 1-1 draw, while Galatasaray were humbled 6-1 at home by Real Madrid.
Juventus have looked in solid form so far this season but, despite creating plenty of goalscoring opportunities, the Bianconeri have scored only 11 goals in six league games to the 17 scored by Serie A leaders Roma.
Tevez, who played under Mancini at City, did not train on Monday and Conte said: "We will be assessing him over the next few hours and make a decision between today and tomorrow."
Conte said it will be "important to create chances" against Mancini's men, but he warned: "We didn't make the most of our chances against the Danes.
"So we have to play well against Galatasaray."
Mancini's arrival will provide a significant boost given the Turks' mediocre start to the campaign, which led to Fatih Terim's recent sacking.
But Conte believes Real's 6-1 win in Istanbul two weeks ago was not a true reflection of the match: "We're not fooled by the large scoreline. It's going to be a tough game."