Republic of Ireland manager Giovanni Trapattoni has called up Aston Villa defender Ciaran Clark to his injury-ravaged squad for the World Cup qualifiers against Germany and the Faroe Islands.

Trapattoni requested Clark on Monday as he struggles with an injury crisis that threatens to decimate his squad for the two crucial qualifiers.

The Italian, already without Kevin Doyle and Richard Dunne, is now set to lose Leicester defender Sean St Ledger and Stoke midfielder Glenn Whelan, who were both due to have scans on hamstring injuries on Monday.

Sunderland winger James McClean has already been ruled out of Germany's visit to Dublin on Friday with a hip injury suffered during his club's defeat at Manchester City and he is also a doubt for the Faroes clash.

A spokesman for the Football Association of Ireland said: "The results of James McClean's scan this morning in Sunderland showed a grade one hip flexor strain which will certainly rule him out for the Germany match and may exclude him for the Faroe Islands. McClean will remain at his club to receive treatment."

In all, Trapattoni will be without six of the side which started the 2-0 defeat by Italy in their final Euro 2012 fixture.

Shay Given and Damien Duff have retired and Sean St Ledger, Glenn Whelan, James McClean and Kevin Doyle having joined Richard Dunne in the sick bay.

Regarding McClean, a spokesman said: "The results of James McClean's scan this morning in Sunderland showed a grade one hip flexor strain which will certainly rule him out for the Germany match and may exclude him for the Faroe Islands.

"McClean will remain at his club to receive treatment."

The spokesman added: "Further to scans earlier in the day, both Sean St Ledger and Glenn Whelan have been confirmed as out of both matches against Germany and the Faroe Islands."

As a result, Trapattoni has drafted Clark with Sunderland's David Meyler and Manchester United's Robbie Brady already on board as additional players.

Los Angeles Galaxy striker Robbie Keane and Spartak Moscow midfielder Aiden McGeady will arrive in time for Tuesday's training.

Trapattoni said he could not rush players back from injury.

"I can't speak as (a) doctor - I am manager. But muscle injuries need time, time, time.

"You don't want a player to play 10, 15, 20, 70 minutes and then have hamstring injury again. I don't want to take risks.

"It's very important, this game. We also need to make our three substitutions to change the game, not because of injuries from before."

The absence of Dunne and St Ledger mean it is likely that John O'Shea will be asked to move into central defence and that Stephen Kelly could replace him at fullback.