The 2011 All-Australian midfielder played only five games in 2013 and Collingwood coach Nathan Buckley said on Wednesday the Magpies doubted the 26-year-old midfielder's ability to regain full fitness.
That was part of the reason the Pies opted not to match Carlton's lucrative offer for the free-agent, paving the way for Thomas to reunite with 2010 premiership coach Mick Malthouse.
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But Thomas rejected Buckley's concerns when he fronted the media at Visy Park, where he was unveiled with his new number 39 Blues jumper.
"The ankle's going really well," Thomas said.
"I'm running and still rehabbing at the same time, just maintenance along the way.
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"With my time at Collingwood, I went and saw all the specialists and I got the same feedback they got and it was passed on to the Carlton footy club.
"I'm not sure why they have those reservations. They're entitled to their opinions on my ankle.
"Their doctors would have their opinions. All I can go off it how it feels and what I've been told.
"So far it feels as good as it ever has. Fingers crossed it holds up and the rest of the body does too.
"I'm pretty confident with the rehabilitation stuff that I can get stuck right into it and get out there in Round 1."
There has been genuine angst between Thomas and the Magpies following his defection, with the midfielder rumoured to have fallen out with Buckley and Collingwood president Eddie McGuire.
He is bracing for a hostile reception from Pies fans when the old rivals clash in Round 7.
"I'm pretty sure we all know how I'll be received – with open arms, I'd imagine," he joked.
"I'm not sure what they'll do. I presume there'll be a few that are pretty disappointed, and if I do get booed, that's all part of it.
"Hopefully it happens a lot of the time, which means I'll have a heap of the ball."
Thomas won't start his pre-season until December 2, but he is already making regular visits to Visy Park to have treatment on his ankle.
"I think every pre-season you go into, you want to try and better the last one," he said.
"Unfortunately for me, that hasn't really been the case over the past two years through injury.
"So I'm just really looking forward to getting stuck into the pre-season, getting the body right and then really getting stuck into the season proper and trying to, along with the rest of the boys, go a long way with this club."
Dale Thomas: Ankle will be fine for Round 1
