Donaldson, joined on the bench by Coco Crisp, who is still dealing with right heel pain, entered the day 7-for-14 against Seattle starter Joe Saunders. Crisp has had plenty success too, going 9-for-30 off the lefty, but their absences were slightly mitigated by the return of Yoenis Cespedes, who had been relegated to the sidelines since Wednesday with a left hamstring strain.
"He's feeling much better," Melvin said of Cespedes, who started at designated hitter. "I saw him run out here earlier today. He was running without any issues. He might not be 100 percent, but hopefully he'll be guarded enough when he's running around the bases."
Melvin said Crisp felt better Friday morning despite playing four innings in Thursday's 18-inning affair with the Yankees. But "whether he's in the lineup tomorrow," he added, "I'm not sure."
Though there's just as much uncertainty surrounding Donaldson, the infielder is encouraged by the progress he's made in such little time.
Donaldson, who exited after 15 innings Thursday after feeling his hamstring "lock up a bit," says he is no longer experiencing "that knotting sensation" he endured for much of the night.
"It didn't feel like a cramp, but it could've been," he said. "I felt like if I was going to run hard, it wouldn't have been good. So I iced it, got treatment last night, and it's a lot better already."
"He felt a lot better than I thought he'd feel today," Melvin said, "so we'll hold out hope he can play tomorrow."
With Donaldson out of the mix, Adam Rosales started at third base Friday.
Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.