BRISBANE Lions ruckman Matthew Leuenberger could return by round 18 after completing his first running session this week since tearing his Achilles tendon in April.

Leuenberger ran on the club's anti-gravity treadmill on Monday to take the first physical steps to recovery from the injury he sustained in round three against Fremantle.

Although the Lions originally diagnosed a six-week stint on the sidelines for the 204cm giant, it was quickly upgraded to 'indefinite' when the full extent of the problem became apparent.

But now that Leuenberger is able to run again, the club expects he will see some action late in the season.

"We anticipate his return at approximately round 18 or 19," football manager Dean Warren said.

"We're being quite cautious and want to make sure that he is absolutely 100 per cent."

Leuenberger, 24, is one of the Lions' most crucial components and the club is treating him with kid gloves.

The anti-gravity treadmill will allow Leuenberger to gradually build the load back through the affected tendon until he can run on solid surfaces in the next few weeks.

Warren said the recruitment of former Adelaide and Western Bulldogs enforcer Ben Hudson and the drafting of Billy Longer had been crucial.

Despite this, he said Leuenberger had been a big loss,

"We were hoping he could play forward more and probably played him and Billy in the same team or him and Huddo in the same team, with Leuey playing forward," Warren said.

"Unfortunately it's (injury) meant we haven't been able to do that, which hasn't been ideal, not only for Leuey's development, but even Billy's development.

"That's why Daniel Merrett has had to play forward a fair bit during the year. If Leuey played forward he would have attracted a tall defender and drawn an opponent and freed up Browny (captain Jonathan Brown) a little bit.

"We had to play Daniel Merrett down there to ensure we didn't have two or three blokes hanging off Browny every contest the ball went into the forward 50."

While Leuenberger is on the road back, the Lions received some bad injury news on Tuesday, confirming young key position forward Bryce Retzlaff had torn his ACL in the reserves match on Saturday and would need a reconstruction.

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