Arizona Diamondbacks right-hander Merrill Kelly has undergone additional testing, including a CT scan, on his ailing back, manager Torey Lovullo told reporters on Tuesday.

Kelly was set to pitch a batting practice session in spring training against Diamondbacks hitters on Saturday, but that session was scratched because of what was reported to be mid-back tightness. He had an MRI on Sunday.

An update on the severity of the injury is expected to come Wednesday.

"Anything is in play here, but Merrill works hard to keep himself in shape so we're going to remain positive," Lovullo said.

Kelly, 37, was a combined 12-9 with a 3.52 ERA in 32 starts for the Arizona Diamondbacks and Texas Rangers last season. He was moved to the Rangers at the trade deadline before he re-signed with the Diamondbacks in the offseason on a two-year, $40 million contract.

In seven major league seasons, the majority of which have been in Arizona, Kelly is 65-53 with a 3.77 ERA in 172 regular-season appearances (all starts). He went 3-1 with a 2.25 ERA, eight walks and 28 strikeouts in 24 innings over the 2023 playoffs as the Diamondbacks reached the World Series, losing to the Rangers.