However he admits the exact timing of his return remains "an open-ended question", depending on how his body responds to the initial phase of his rehabilitation program.
Collingwood indicated on Tuesday that it hoped Thomas would be available by round 20 and able to play some games before the finals, should the Magpies qualify.
Coach Nathan Buckley admitted there was some apprehension around whether the midfielder would play any meaningful part in the season but the chance to have him back 100 per cent right was a better option than nursing him through at 75 per cent fitness.
The decision to operate on Thomas had come after the club had indicated he would merely rest for a fortnight in the hope the ankle would settle down.
However both the player and the surgeon had a change of heart and an operation was decided upon over the weekend.
Thomas told radio station Nova FM the surgeon told him that it was a good call.
"It was a good thing we didn't wait a couple of weeks because we would have wasted a bit of time," Thomas said.
Describing the injury as "strange", Thomas said his surgeon had been a little apprehensive about what course of action he should take because the injury – which occurred when Thomas received a kick to the leg against Hawthorn in round three – was uncommon.
Thomas is a restricted free agent who comes out of contract at the end of the season.
He told AFL.com.au before the season started he would delay contract negotiations until he was injury free and playing good football. At that stage Thomas was recovering from a pre-season operation he had on the same ankle to repair a different injury.
Collingwood football manager Geoff Walsh said Thomas' new injury would not have any impact on the progress of contract negotiations.
Thomas has played 157 games for Collingwood, including a premiership. The 25-year-old was All Australian in 2011 and finished third in the club best and fairest in the Magpies' premiership year.
