Mark Hughes has urged international coaches to stop compromising the fitness of players as the Manchester City manager faces up to the prospect of losing Martin Petrov for the rest of the season. The winger suffered a knee injury playing for Bulgaria this week.

City were among the Barclays Premier League clubs hardest hit by a bruising international calendar, with Hughes fearful that Petrov could be out for six months after appearing to damage his anterior cruciate ligament during Bulgaria's goalless draw away to Georgia on Wednesday. City should discover the full extent of the problem on Monday after a series of scans over the weekend.

As a former coach of Wales, Hughes has some sympathy with his international counterparts, but the City manager believes that more common sense needs to be applied when assessing the fitness of players before international games.

Hughes was annoyed with Plamen Markov, the Bulgaria coach, for playing Petrov for 90 minutes against Italy last Saturday and from the outset against Georgia, even though the winger had played only 25 minutes of football for City since returning to the first team after five weeks out with a hamstring injury.

“The fear is that Martin has done his anterior cruciate ligament, which would mean five or six months out,” Hughes said. “It is a difficult job being an international manager. They only have a certain amount of games to make an impression and sometimes even to keep their jobs, so they have to have as many key personnel at their disposal as they can. But sometimes that will compromise the players - they maybe play for too long. Maybe on occasions there needs to be a little bit more thought for the player himself and his future at his club.

“He had only had 20 minutes in one game [against Omonia Nicosia in October] and five minutes in another [against Liverpool three days later] prior to going away and playing 90 minutes for his country. It is a big ask and players are at risk on occasions if they have not had the required amount of time on the pitch prior to joining the international squads.

“If I could have chosen, he would have played maybe one half. Bulgaria knew his recent injury history and Martin would have told them how much he has played in recent weeks, but international football is something that players aspire to and they are proud to play for their countries, so that is always a worry when they are coming back from injury.”

Although there was better news for City on Robinho, who is expected to be fit for the Premier League game away to Newcastle United on Monday evening despite being substituted with a thigh injury during Brazil's goalless draw against Colombia in Rio de Janeiro on Wednesday, Petrov's absence will come as a blow to Hughes.

Joe Hart, the City goalkeeper, was also called into the England party for the World Cup qualifying match away to Belarus on Wednesday. Hart and David Wheater, the Middlesbrough defender, were drafted into Fabio Capello's senior squad immediately after helping England to secure a place in the European Under-21 Championship finals at Wales's expense on Tuesday, but both were spectators in Minsk.

“It was a long way to go just to sit in the stand and he had played two games in a short space of time as well,” the City manager said. “But we were not going to stand in the way of players progressing their international careers. What value it was to Joe to go out there and watch the game is open to debate, but he would have been around the senior squad and gained an understanding of what it is like under Mr Capello, so maybe it was the right decision.”