"He just had a muscle pull or something," Tippett said, according to azcentral.com's Sarah McLellan. "I don't think it's too serious."
Doan, 36, left halfway through the scrimmage and might not participate in Thursday's practice. He had offseason surgery to repair sports hernias on each side of his abdomen, which limited his mobility last season.
The scrimmage at Jobing.com Arena was held to benefit the 19 firefighters who lost their lives fighting a forest fire while trying to save the town of Yarnell, Ariz.