Forward Grant serves the third game of a four-match ban, while midfielder Cavanagh continues to struggle with a calf problem.
"He's had a pain killing injection into his calf but he'll probably be fit enough to train with us next week," said manager Keith Hill on Rochdale's official website.
New signings Ritchie Jones and Michael Rose were named on the bench for last weekend's 1-0 win over Torquay and could push for starts, while Hill is not expecting any further arrivals before the trip to Underhill despite his best efforts.
"It's unlikely but we've got plenty of irons in the fire," he added. "We've got to appreciate the hard work that players have done so far and whether I do or do not recruit it will just be competition for places."
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