There is a serious doubt over Darren Purse. City only have one centre half, Roger Johnson, after it was revealed Glenn Loovens would miss the rest of the season. Purse has played some reserve team football and was expected to return this Saturday. That now appears in some doubt.
'Darren is probably the biggest doubt of the three,' Jones told the Echo.
'I don't go in the medical room because I have good staff in there.
'Michael did have a small tear to his hamstring, but he has made good progress. Riccy had a tear in his groin, but that has healed pretty well.
'Tomorrow will be the big day for both of them. If they can take part in training then they have a chance.
'We have to remember the next game, against Sunderland at home, is the important one.
'Sometimes you look at future games and try not to rush players back.
'We will, of course, be governed by medical opinion and what the scans tell us, but if they are ready Michael and Riccy will play.
'Healing is an individual thing. Some people heal quicker than others.
'I always try to avoid putting a timescale on how long players will be out because of that.
'Right now I am not going to rule them out.'
Saturday's game is building up nicely with tickets selling well. Sunderland have sold their 2,000 allocation and a large crowd is expected.