The tall forward, who was traded home to Perth in the off-season, lasted just 20 minutes in the NAB Challenge match against the Western Bulldogs at Docklands on Wednesday before hobbling to the bench with a sore hamstring.

Physios began treatment on his upper right leg but with the first small stretch Gumbleton flinched in pain.

A trainer arrived minutes later with the red vest and he was out of the game.

Gumbleton has played just 35 games since his debut in 2007 with his career stalled by a procession of hamstring strains and back-related problems.
 
"It's really disappointing for him, he'll be really flat because we know his history of back-hamstring stuff," Lyon said.

"He hadn't missed a session and if anything, we'd lightened off (with him) a little bit this week. I feel for him, because he's worked his hardest and shown strong character.
 
"They said it's just a hammy, there's nothing off the bone or anything. They have to assess, but it's a hamstring - they're typically three weeks. It could be more, but I wouldn't have thought."
 
Lyon said it was a short term problem and he remained confident that long term the investment in Gumbleton would pay off.
 
Bulldogs coach Brendan McCartney said there was "a lot to like" about his side who got in front in the second term before being overhauled in the second half despite a final term rally to lose by 28 points.  
 
He foreshadowed a shift to defence this year for Shaun Higgins who played his first game back since round three last year. Tom Williams also go through his first game since round 10 and after playing only five games in two years.
 
"Tommy did what he does best and threw himself on his shoulder and it held together.

"We are going to have a look at Shaun in some different positions and he is that bit of that polish I am referring to (in defence) but he is going to have to learn the other side of the game when he is down in the backline and he will."
 
McCartney said recruit Stewart Crameri played well in patches but lapsed into some habits they had discussed and were trying to work out of his game.
 
"We didn’t bring Stuey to our club to be a 100 goal kicker, it is to help our forward line work and his athletic prowess came out tonight against some pretty good defenders and pretty experienced defensive team."
 
He said he was confident Bob Murphy and captain Ryan Griffin would both play in round one with Griffin a possibility to play against Carlton in a practice match. If he misses that encounter he is likely to play an intra-club game before the season-opener.
 
"We are very confident they will be right to go," he said.