Roberto Mancini is concerned over Vincent Kompany's recovery from a calf injury with the Manchester City captain having returned to Belgium for international duty rather than staying at the club to ease himself back to fitness.
The City boss, who left Kompany out of the squad for the 3-0 win over Sunderland at the Etihad Stadium on Saturday, would have preferred the defender to remain at the club's Carrington training ground during the international break in order to have him available for selection ahead of the champions' visit to West Brom on Oct. 20.
However, the Belgium captain met up with Marc Wilmots' squad after watching City's convincing weekend victory and announced his intention to play for his national side, tweeting: "Injury isn't too bad but I was carrying it since the last game. Will have to try and get fit for internationals!"
A source close to City told Goal.com: "Roberto has always liked players who are willing to put themselves on the line, but he's certainly raised his eyebrows over this one after Vincent missed the Sunderland game. He would rather the medical team kept a close eye on him while the club has a quiet couple of weeks at Carrington."
It is the third time in six months that Kompany has suffered an injury to his calf after initially limping off with a knock seven minutes into City's 1-0 loss to Sporting Lisbon in March, and then again in the pre-season fixture against Arsenal in Beijing at the end of July.
As a result, Mancini is wary of rushing his captain back and is concerned that the center half would be risking further damage if he were to play in Belgium's crucial qualifiers against Serbia on Friday and Scotland the following Tuesday.
Kompany, 26, is keen to play a pivotal role in Belgium's qualification process for World Cup 2014 and has started in each of the Red Devils' previous two qualifiers alongside fellow Premier League defenders Jan Vertonghen and Thomas Vermaelen, with Wilmots' side picking up four points from a possible six.
In September's international break, Mancini blasted Sergio Aguero's call-up to the Argentina squad as "ridiculous" after the striker sustained a knee injury in the champions' clash with Southampton on the opening day of the season.