Boggs received treatment for lower back tightness on Sunday morning after notifying the staff of the issue after his appearance on Saturday. Boggs said his back tightened when he faced Matt Kemp with two outs in the eighth inning. The right-hander ended up retiring Kemp on a groundout without seeking medical attention.
"I've dealt with it a little bit in the past and as far as that scale, it's the least," said Boggs, who ranks first in the National League with 30 holds. "I was able to continue to pitch. I just got some treatment today and see how it feels."
Boggs has been the Cardinals' go-to reliever in the eighth inning this year. Mujica, the Cardinals' seventh-inning man, was also likely to have to sit on Sunday. While healthy, Mujica has pitched in each of the last three games and in four of the team's last five.
Workload concerns could force Matheny to have to look elsewhere for late-inning help. Closer Jason Motte, who took the loss on Saturday, was available.