Rovers are struggling at centre back with Gordon Greer and Adam Lockwood ruled out through injury and any deal for Manchester City target Matt Mills will not be concluded in time.

Doncaster were beaten 1-0 at Morecambe on Tuesday night with a patched up squad in which right back James O'Connor featured as sweeper in the first half with big striker Gareth Taylor switching to centre back after the interval.

O'Driscoll said: "We're having to mix and match at the moment, and are a bit thin on the ground in one or two areas, so it might be an opportunity to have a look at a couple of trialists."

The Doncaster boss has been inundated with offers from agents who have European players on their books and are keen for them to make the move to English football.

He said: "According to their cvs they are all outstanding players and going to be the next big name in the game.

"Obviously all the top players are touted around to Premier League clubs where the big money is but there are some who see an entry route through the Championship.

"Even taking into account all the hype some are obviously decent players and may be worth taking a look at.

"There are one or two from Lithuania and France who look interesting but they could be anywhere from Europe.

"It all depends if they are willing and available to fly over for a game."

Former Scotland international centre back Steven Pressley has returned home after training with the club and does not figure in O'Driscoll's current plans although he said neither party had closed the door on each other.

He said: "We are looking for someone younger and quicker and Steve admits himself he's a bit rusty and needs to work on his fitness.

"But he is a player with a tremendous attitude and we agreed to keep in touch if the situation changes."

Rovers have now settled on a fee with Manchester City for Mills after new boss Mark Hughes agreed to let him go and are trying to finalise personal terms with the player.

O'Driscoll said: "There are other clubs keen but he has indicated we are his first choice and it just depends if we can agree terms."

Rovers tied up a deal this week for 19-year-old striker Tomi Ameobi who O'Driscoll rates as a player for the future.

New striker Darren Byfield and fans' favourite Jason Price are hoping to be fit for Saturday's friendly and Rovers received another boost before the clash.

Negotiations to tie top players Ritchie Wellens, Brian Stock, James Coppinger and James O'Connor to longer contracts are virtually complete and O'Driscoll added: "They are all keen to stay at the club and face the challenge of the Championship together.