Garcia has pitched six innings, faced 21 batters and struck out 10 with one intentional walk. He struck out two of the three batters he faced in both games against Seattle, after striking out four in two innings Friday night in Arizona.
Garcia, veteran Joel Peralta and lefty Paco Rodriguez have inherited late-inning duties while Chris Hatcher and J.P. Howell have struggled, although Hatcher looked much improved while striking out two of the four batters he faced in Tuesday night's 6-5 win after taking over for Howell, who struck out two.
Hatcher, the presumed closer coming out of a rocky Spring Training, is still viewed as the likely setup man to the injured Jansen once everybody is at full strength.
"He has good stuff and a lot of weapons, but if he doesn't use them in the right combination, that kind of goes away," said Mattingly.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.