Walden's injury came after he impressed with the two perfect innings in the Aug. 21 win over the Mets. The right-handed setup man struck out four of the six batters he faced and totaled 25 pitches.
"Those might have been the best two innings he's thrown or anybody's thrown," Gonzalez said. "He was nails. I think he went through six outs."
With Walden ailing, Luis Avilan made his fourth appearance in five days in Wednesday night's 3-2 walk-off win over the Indians. Avilan loaded the bases with just one out in the eighth and then minimized the damage to one run. But the usually reliable left-handed setup man has allowed a run in three of his past seven appearances entering Thursday's series finale.
Avilan had allowed just one run, which was unearned, in the 35 appearances that preceded this stretch.
While Avilan could understandably be feeling some fatigue as he nears the end of his first full Major League season, Gonzalez said he has not seen any reason to be concerned.
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.