Northampton Town boss Chris Wilder says he did not rush Marc Richards back too quickly, after League Two's top scorer suffered another hamstring injury.
The 32-year-old could be out for up to six weeks, having previously been sidelined for a fortnight.
Richards returned off the bench in Saturday's draw with Wycombe, but came off in Tuesday's Johnstone's Paint Trophy win at Portsmouth.
"He wanted to play Saturday," said Wilder. "But we decided to wait."
Talking to BBC Radio Northampton, Wilder continued: "It's disappointing for the player and ourselves. He got through half an hour on Saturday and did work this week. But it's a blow."
Richards, who has eight goals this season, has not injured the same hamstring that saw him initially sidelined.