Mayer (forearm) had his rehab assignment paused due to a bone bruise in his right foot, Justice delos Santos of The San Jose Mercury News reports.
Mayer will rest through the weekend before being re-evaluated early next week. He initially landed on the 10-day injured list in late June with a left forearm stress reaction while still with the Red Sox, before getting sent west at the trade deadline. The 23-year-old has played four rehab games with Triple-A Sacramento, going 6-for-17 with one home run and a 2:9 BB:K. Mayer had appeared in line to make his Giants debut early next week, but that plan is likely on hold.