MATTHEW Leuenberger is back running and hoping to play senior football before the end of the season.

The Brisbane Lions ruckman has been sidelined since round three with Achilles tendonitis but is now working on a comeback timeframe of four or five weeks.

Leuenberger did a skills session at the Gabba on Monday and completed three quarters of the Lions' main training session on Wednesday and said he now just needed to regain fitness.

With a return playing date either round 18 or round 19, the 204cm West Australian said he was hopeful of being in the seniors before the end of 2012.

"That's my goal. I haven't talked about it with the coaches, it's more about just getting back fit enough ready to play again but my goal is to get back in the senior side and re-establish myself in there," Leuenberger said.

"It's awesome. You can see the light at the end of the tunnel, it's all coming to an end now. The next month will hopefully go really quick and I'll be out there and playing before I know it."

The 24-year-old said the tendonitis was a problem that had dogged him for most of his career.

He has undergone two blood injections into the tendon, and mixed with a mountain of strengthening work around that and the calf, has made his way back to training.

"In the past I've had it and then it disappeared, reappeared, it just comes and goes, it's unpredictable," he said.

"I've held out and tried to be optimistic and hoped it would disappear but unfortunately the worst case scenario ended up happening.

"I think I'm going to have to, for the rest of my career, have a pretty diligent exercise regime in terms of keeping on top of that area of my body because I've had a history of it."

Leuenberger is undoubtedly one of the Lions' most crucial young cogs and is signed until the end of 2013.

He said watching the team perform well in the past month had been exciting more than frustrating.

"The past few weeks, in my opinion, they've been playing a real good standard, and it's real promising the way they've gone about it and I've loved watching them. I'm pretty enthusiastic to get back out there and join in."

Michael Whiting covers Brisbane Lions news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting

The views in this story are those of the author and not necessarily those of the clubs or the AFL