Eovaldi was scratched from his start on Thursday, at home against the Braves, due to a tight back. Best case scenario is the hard-throwing right-hander will pitch during the series at Philadelphia next week.
Right now, it doesn't appear that would be on Monday. Sam Dyson is likely to get the nod that day.
"He is feeling better," Marlins manager Mike Redmond said of Eovaldi. "That's good. Hopefully, we get him back out playing catch soon. We'll see. I don't have a date as far as when he will be able to pitch."
Dyson threw three innings of relief against the Braves on Thursday, and he is ready to go on Monday. But a final decision hasn't yet been made.
Mathis, meanwhile, is also improving. The veteran catcher bruised his thumb while blocking a pitch on Monday.
A second X-ray also came back negative, and the swelling is subsiding. Mathis may start swinging the bat in the cages on Saturday. The earliest he could be ready is Sunday, but that may be optimistic.
"Each day he seems to be getting better and better," Redmond said.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter