Kerr's recovery from a torn hamstring in round four has been slower than expected, with the 27-year-old still some weeks away from resuming full training.
St Kilda's Nick Riewoldt and Hawthorn's Josh Gibson suffered similar injuries a week before Kerr and are already back playing.
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But with the Eagles sitting in last place on the ladder and no chance of reaching the finals, Worsfold said Kerr's major aim was to get back to full training rather than playing again this year.
"It's unlikely we'll play him, certainly at AFL level," Worsfold said on Wednesday.
"His aim still is to show he's back ready to play."
"The program is get back doing full training, full train for three or four weeks to get your conditioning base up and then a player would be available to be considered for selection.
"Then whether we select him or not, I would suggest we wouldn't, but that's not part of it.
"His aim is to train enough to say 'I could play if we all wanted me to'."
Worsfold said West Coast's 32-point win over Essendon last week, which broke a seven-game losing streak for the Eagles, had lightened up the mood at the club.
"It's certainly more fun than losing," he said.
"The players' attitudes have been very steely and very positive throughout this whole season.
"To their credit they've worked extremely hard and haven't got down on anything.
"They haven't dropped away or at any stage looked like they're starting to not enjoy coming to training and trying to improve."
"It was a good reward from them."
