The Giants saw their bullpen crumble Monday night, losing to the Diamondbacks, 9-7, in 11 innings.
And, they couldn't use one of their most reliable arms, George Kontos.
Kontos, 30, had tests done earlier in the day on his right arm, which revealed he has a flexor strain. He is expected to go on the DL with a roster move to be made Tuesday.
"We had some tests done today, it's been bothering him for a little bit," Giants manager Bruce Bochy said after the loss. "Sure enough, it showed a flexor strain."
In a league-leading eight appearances, Kontos is 0-1 out of the bullpen with a 1.59 ERA. He has only allowed one earned run all season long.
"He felt it a little bit in spring training and he's battled it a little bit," said Bochy.
The same injury has put Giants reliever Sergio Romo on the 15-day DL.
"Pretty amazing, really. His stuff was pretty good the last couple outings with the flexor strain. But he needs a break," Bochy said on the ailing Kontos.
In six innings of work, the Giants' bullpen allowed five runs to the D'backs. Chris Heston took the loss, giving up two runs in just 2/3 of an inning.
The Giants are now 7-7 on the season after falling to Arizona Monday night.