McMahon has been sidelined for the last month after suffering a thigh injury on the training pitch in the build up to Bolton Wanderers away match in September.
Frustratingly, the 30 year-old had only just come back into the reckoning at that stage having sat out the previous four weeks following a similar problem picked up towards the end of the Coventry City home win back in August.
McMahon joined in with both Monday and Tuesday's sessions at Apperley Bridge but City chief Stuart McCall is yet to decide whether he will be in contention or not for this weekend's trip to AFC Wimbledon.
McCall said: "Tony has been out for a long time in total and he will need some training under his belt.
"Tony has been back training with us before and it went again, but this time he feels a lot better.
"He naturally wants to be back as soon as possible.
"He is a great character to have around the dressing room and it will be good to have him back in contention for the games coming up."
McCall is hopeful that James Meredith will be able to join McMahon and the rest of his City team-mates for training at some point this week.
The Australian left back has missed City's last two games after injuring his ankle during the recent away match at Oxford United.
McCall added: "Mez (James Meredith) was keen to be involved last Saturday (vs Sheffield United) but he was still feeling some stiffness in the ankle.
"He has been working with Chris (Royston, Head Physio) recently - he just needs to get used to running on the joint again without any discomfort.
"You need someone to be fully fit before we can think about bringing them back into normal training."