But there are no guarantees he will walk back into the centre of defence where Krystian Pearce and David Mirfin have been in fine form.
Diamond proved he had shaken off a slight strain in the reserve game at Rotherham on Tuesday and manager Steve Evans said: “I was told by Paul (assistant, Raynor) he was excellent. I watched the game back and he was excellent.
“We want our captain in the group. When he’s not in the group it just takes a little something away from us.
“If he trains properly today and tomorrow he will be back in contention for Saturday.
“But I don’t have to change it, though, and one thing you have to say is that Krystian Pearce has stood up to the challenge.
“He picked himself last season. He used to turn up and get ready, he didn’t wait for the team!
“Him and David Mirfin have been excellent. Every time David has worn a Stags shirt in a competitive game he has been outstanding.”
Evans kept his side unchanged for last Saturday’s 1-1 draw at Carlisle but several players staked a firm claim for a start with their performances in the reserves.
“Paul gave me a good report on the reserve game,” said Evans.
“I have watched the footage of that and now have an idea of where people are.
“We just want to make sure we make the right decisions and pick the right team to play Grimsby on Saturday as it’s a big seven days for us with two derbies sandwiching playing Gareth Ainsworth’s team. It is a really tough seven days.
“Nothing beats competitive minutes and going up against seven or eight lads who ply their trade in the Championship was good for us on Tuesday.
“Despite the result, we had a dominating performance and there were three or four very good individual performances trying to get into the team on Saturday. That’s why we play these games.”