The pre-Lions tour injury count began at the weekend as Tomas O'Leary withdrew with a broken ankle.

Here we take a look at some of the leading contenders to replace the Irishman and join fellow scrum-halves Harry Ellis and Mike Phillips in the squad.

Mike Blair - Edinburgh & Scotland
One of the favourites to step up, the Scottish skipper was among those seen as unlucky to miss out on the original squad when he was passed over for the in-form O'Leary.

Blair demonstrated he was in good nick with an impressive display for Edinburgh at the weekend and it would be no surprise if coach Ian McGeechan sees him as an ideal candidate for the midweek team.

Danny Care - Harlequins and England
Care lost out to Ellis in the battle to become England's Six Nations no.9 but after an impressive season at club level he could yet force his way into the Lions frame.

Previous ill-discipline, most notably his Six Nations sin-binning against Ireland after being on the pitch for just 12 minutes may work against the Harlequins man, but at just 22-years-old, youth could be key if the powers-that-be decide to take a chance.

Dwayne Peel - Sale Sharks & Wales
Peel was the youngest player to make the tour four years ago but after missing out on this year's Six Nations and with the Wales coaching team making up the bulk of the Lions backroom, it looks unlikely he will be taken.

Additionally, his season with Sale has now drawn to a close meaning he has no further chance to impress the selection panel while his rivals do. An outsider.

Chris Cusiter - Perpignan & Scotland
Cusiter currently plys his trade in France but a lack of match time could significantly hinder his chances of a call-up.

He toured with the Lions in 2005 and performed admirably as the midweek scrum-half which should stand him in good stead with McGeechan.

Putting past performances aside however, compatriot Blair would have every reason to ask questions if his international rival was chosen ahead of him this time around.

Peter Stringer - Munster & Ireland
Veteran Stringer is being seen as an outsider but he would have no trouble gearing himself up for what would be a fitting career swansong.

He featured prominently during the Six Nations and showed he can still cut it on the big stage with a man-of-the-match performance against Scotland.

If opting for Care would mean a bold injection of youth, Stringer's selection would certainly add another experienced head to the party.