PHOENIX — The Braves could add a familiar and well-rested power arm to their bullpen this week in Colorado after Jordan Walden impressed in his second rehab appearance Sunday at Triple-A Gwinnett.

Walden had two strikeouts and one walk in the first inning of a 4-2 victory against Rochester, and threw 12 strikes in 19 pitches.

Braves manager Fredi Gonzalez had said Saturday that if Walden had no setbacks the plan would be to have him join the Braves on Tuesday in Colorado for the second game of their four-game series against the Rockies.

“I felt good out there, hamstring felt good,” Walden said after Sunday’s appearance. “I didn’t have any issues with it again, so that was a positive. I walked the first guy and I wasn’t very happy with that. I didn’t feel like the command was there, but I battled through and got a couple strikeouts.”

Walden had five strikeouts and one walk in two innings in two appearances for Gwinnett on Thursday and Sunday.

The hard-throwing setup man has missed just over a month with a strained hamstring. When Walden returns, Gonzalez said he would be back in his role as a seventh- and eighth-inning setup man.

Setup man David Carpenter has struggled in recent weeks, posting an 8.31 ERA and .415 opponents’ average in his past eight appearances. He gave up two hits, a walk and the winning run in the 11th inning of Saturday’s 4-3 loss at Arizona.

The Braves have been quite pleased with the performance of hard-throwing rookie Shae Simmons, who was called up from Double-A on May 31 and has excelled when thrust into high-pressure situations in his first major-league callup. Simmons pitched a perfect eighth inning Saturday before three of the next four Braves relievers gave up a run apiece, including blown saves for Craig Kimbrel in the ninth inning and Anthony Varvaro in the 10th.

It was the first loss for the Braves in 28 games when they led after eight innings.

Simmons already had been credited with three holds and one save in five appearances, with three strikeouts and one walk in 3 1/3 scoreless innings.