Adelaide veteran Scott Thompson is "touch and go" for Round One after suffering a minor hamstring injury at training.

Thompson has been ruled out of the Crows' NAB Challenge clash with Geelong on Thursday night at Simonds Stadium and is likely to miss the Club's final clash against Port Adelaide on March 21.

Coach Phil Walsh described the injury as a minor setback but the midfielder, who turns 32 on Saturday, remains in doubt for the season opener against North Melbourne on April 5.

"Thommo's had a slight setback with his hammy so he's probably touch and go for even next week (and Round One)," Walsh said.

"We'll just monitor that one as we go along.

"We've still got four weeks (until Round One), most hamstrings are only three weeks but he did have a slight setback."

See Adelaide’s 29-man squad for the clash with the Cats

Thompson suffered some back-related hamstring issues last season but Walsh said this twinge is not related to those issues.

"They tell me it's not (related)," Walsh said.

"It's really minor but at this time of the year we want Thommo 100 per cent fit and ready to go."

Young midfielder Matt Crouch has also been left out of the squad to face Geelong as he continues to recover from ankle surgery, while ex-Hawk Luke Lowden is still being monitored after undergoing a modified training program before Christmas.