Assistant coach Wayne Campbell said on Wednesday that Coughlan might be back for the third round of the NAB Cup.
"He'll have surgery tomorrow – I think it's just a small meniscus tear in the knee that he's had reconstructed a couple of times," Campbell said before training at Victoria Park.
The 2003 best-and-fairest has had two knee reconstructions which led to chronic hamstring issues which have combined to keep him sidelined since round 12, 2006.
Coughlan, 26, looked good in the club's intra-club match last Thursday, but felt soreness in the knee afterwards.
"I think it sounds worse than it is," Campbell said.
"We think he'll be back training in a couple of weeks, so … 'Mark Coughlan' and 'knee' doesn't sound great, but we think it's only a minor setback for him.
"I think this is a really minor hiccup, so I think he sees it as that as well.
"He was going unbelievably well and we were really surprised and rapt how well he was going.
"Certainly with two knee reconstructions he's been through enough hell in the past.
"It's not ideal for him, but certainly it's not catastrophic by any stretch."
Campbell, who moved back to the Tigers in the off-season after a couple of years as an assistant at the Western Bulldogs, said Coughlan had been travelling beautifully until the injury.
"He's just had a really good run of things – the improvement in him in three or four months since we came back on October 17 has been remarkable, to the point where it was just going to be a fairytale story.
"And we think it probably still will be.
"If all went well, he could play NAB (Cup round) three – whether that happens or not, I don't know, but certainly round one (of the regular season) versus Carlton is not out of the equation."
Coughlan had successful treatment on his troublesome hamstring in Germany last season, which allowed him to return to the track with Coburg for the last few games of the year, and that success had flowed through into the pre-season.
Just three weeks ago he was looking forward to his first AFL game in nearly three years, and declared: "It's pretty exciting – I've done most of the pre-season, and I'm just trying to get through the rest of January now and hopefully put my hand up for that first game against Fremantle over there.
"I'm feeling pretty good in the body - this year's just been a bonus, being able to do a pre-season and the group's looking pretty good for the year, so I'm pretty excited about maybe being a part of that."
