The Bulgarian midfielder - Villa's player of the year last term - suffered a dislocated shoulder injury at La Rosaleda stadium in Malaga and now looks certain to spend an extended spell on the sidelines.

Villa went into the match needing to beat Group C leaders Atlante of Mexico by two clear goals if they were to reach the last four after suffering a 1-0 defeat to Malaga in their opening match of the pre-season tournament.

And things were looking bad for Villa when Curtis Davies put through his own goal in the 20th minute to give CONCACAF Champions League winners Atlante, who beat Malaga 3-1 in their first outing, an early advantage.

However, Villa hit back and were on level terms before the break when young substitute Marc Albrighton netted after Atlante goalkeeper Federico Vilar had saved John Carew's header.

Albrighton had replaced Petrov in the 21st minute after the Bulgarian midfielder suffered what the Villa website later reported was a dislocated shoulder.

Villa started the second half still needing two more goals to get through to the semi-finals, and they managed to get both of them within 15 minutes.

Carew fired home Villa's second just three minutes after the restart and then England winger Ashley Young headed home Albrighton's cross on the hour mark to put the Premier League side 3-1 ahead and that was enough to secure their semi-final spot.

Martin O'Neill's men will now meet either Porto or Besiktas - who are currently playing each other in Seville - in Friday's semi-final, while the other semi pits big-spending Real Madrid against Italian giants Juventus.