Grella has been out for the past month with a groin injury, the latest in a series of setbacks since joining Rovers two years ago. Allardyce concedes the Australia international has been unable to get a regular run in the side because of a number of niggling injuries. "He can't seem to get a run of games to maintain the level of fitness we call match fitness," said Allardyce. "Vince has been unable to do that in his entire time here and has always broken down in some way. "The concerning thing is it is not a particular area that continues to break down, it is always somewhere different. "He is experienced, we know how good a passer he is. He has had an impact on the team when he has been available but unfortunately we haven't been able to keep him on the pitch long enough."
