Manchester City 's faltering season has been hit by another blow after it emerged Vincent Kompany may miss the remainder of the campaign . The influential captain was substituted during Sunday 's 4-2 derby defeat at Manchester United - a result that effectively ended their hopes of retaining their title and left them looking over their shoulders as they attempt to secure Champions League football . And the under-fire Chilean boss , speaking ahead of Sunday 's visit of West Ham United , revealed Kompany may not be seen again this term . Vincent Kompany is not guaranteed to return this season after injuring himself in the Manchester derby . Kompany could have been sent off for a challenge on Daley Blind before being substituted last weekend . 'He is injured , ' said Pellegrini . 'It 's very difficult to know . He has a muscle injury . We do n't know how many weeks . We do n't know if he will be fit from now until the end of the season . ' Pellegrini claimed he did not feel under pressure despite speculation mounting that he may be sacked at the end of a disappointing year . Manuel Pellergini claims he is not concerned by the mounting pressure over his position at the Etihad . Bundesliga managers Jurgen Klopp ( left ) and Pep Guardiola have been linked with a move to City . 'My pressure is always the same , ' he said . 'To try and win every game . Last year ( there ) was more pressure when we were fighting for the title . It 's the worst moment but the pressure to recover is not same . ' He added that he was not hurt when he heard other managers such as Bayern Munich boss Pep Guardiola and departing Borussia Dortmund manager Jurgen Klopp linked with his own job . 'Every time you manage an important club , every big club , if you do n't have results the club deserves everyone talks about changing manager . I trust a lot in the work I do . Nobody is happy with results . It 's not logical to sack the manager . I do n't think that 's the right diagnosis . ' The reigning champions have slipped from serious title challengers to fears over not finishing in the top four . Pellegrini added that he took the blame for a record that his seen City win just four of their last 15 matches . 'It 's always my responsibility for the squad . I choose the players . I always trust my players and its always my responsibility . ' Pellegrini is also expected to be without long-term injury victims Stevan Jovetic and Wilfried Bony for the visit of Sam Allardyce 's Hammers . He added that James Milner ( knee ) and Gael Clichy ( groin ) would also miss out .
Vincent Kompany was injured in the Manuel Pellegrini derby defeat by United . Manchester is not sure if the Belgium star will return this season . The Premier League champions face West Ham at the Etihad on Sunday .