Marc Murphy says he is likely to play in Round 1 against Richmond, but the Carlton captain concedes he still has "a bit of work to do" over the next week to prove his fitness.

Murphy only returned to contact training two weeks ago after undergoing a left shoulder reconstruction last September and a more minor follow-up operation three months later.

Murphy told reporters on Thursday that his shoulder had been feeling better with every contact session he had completed recently.

But he said he would need to get through a match simulation session at Ikon Park on Friday and the Blues' remaining training runs before he could take his place in the season opener.

"I'm likely. I've still got a bit of work to do over the next week; there are still a few boxes that need to be ticked," Murphy said at the AFL Captains' Day.

"Having an injury is never ideal and having to go in a couple of times (for operations) to make sure it's all right is not ideal, but coming out of the one I had in December to clean (my shoulder) up a little bit I'm really confident that that's got the job done.

"Better late than never, I suppose, to get it right. It's on track for where we want it to be and where we thought it was going to be in December.

"(I've) just been getting incrementally more contact and more tackling into (my shoulder). So I've been building that up for the last few weeks to a really good point where I can really test it out now." 

Murphy's shoulder injury sidelined him from just one week of running over the pre-season, so the Blues skipper is confident he will be fit enough to run out a full game if he plays against the Tigers – even with the reduction in interchange rotations from 120 a match to 90 this season.

Meanwhile, Murphy leapt to the defence of teammate Dale Thomas after widespread media criticism of the former Magpie's wayward kicking in the Blues' NAB Challenge loss to the Sydney Swans last Friday night.

Some commentators even questioned whether Thomas was still in Carlton's best 22.

"I don't understand why he's the whipping boy as much as he is," Murphy said.

"He missed a couple of kicks that I think he'd like to have back, but it's NAB Challenge and I think you've seen a lot of blokes in this NAB Challenge period miss kicks.

"I think because it's 'Daisy' Thomas they just like getting stuck into him, but the way he's trained and the way his body looks, the condition he's in, he's set to prove a lot of people wrong.

"I couldn't be happier with the way that he's been training and the boys and the coaches are right behind him.

"I think you'll see a really good Dale Thomas this year."