Alex Ferguson is set to throw the newly-installed Republic of Ireland Under-21 captain John O'Shea into action for Manchester United's Champions League qualifier against the Hungarian champions Zalaegerszeg on Wednesday.

O'Shea, who is inexperienced at this level, gets his chance following the injury to Rio Ferdinand at Old Trafford on Saturday.

The England defender went over on his ankle after hurdling his goalkeeper, Roy Carroll, and landing awkwardly. He will have a scan today to assess the extent of the damage.

As well as the midweek game, Ferdinand is more than likely to sit out Saturday's Premiership opener against West Bromich Albion. If the £30 million defender has nothing more than a badly sprained ankle, he could be back within a couple of weeks.

Should the damage turn out to be more serious, he could be absent for up to a month.

O'Shea made his full international debut a year ago this week, and Ferguson has been predicting for some time that the former Waterford United player will become one of the game's top defenders.

But Ferguson will be keen to further strengthen his defensive options and is expected to finalise the £5 million transfer of the Rennes left-back Julien Escude this week, in advance of the August 31st deadline for the Champions League.