SCOTTSDALE, Ariz. -- After spending the first week of Cactus League games on the sidelines, All-Star closer Corey Knebel and the rest of Milwaukee's mainstay relievers joined the fray on Thursday.
Knebel, left-hander Josh Hader and free-agent addition Matt Albers made their spring debuts in a 6-1 win over the D-backs, to be followed Friday by Jacob Barnes, Jeremy Jeffress and another newcomer, lefty Boone Logan, against the Mariners at Maryvale Baseball Park. The fact the Brewers didn't rush any of those relievers into Cactus League play was an indication that all six are ticketed for what is expected to be an eight-man Opening Day bullpen.
"I think at this point, all the guys who haven't thrown yet are pretty excited to see a hitter and how their stuff is playing right now," Barnes said.
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Why the wait? Relievers don't need nearly the time to build arm strength for Opening Day, so the Brewers took a conservative approach. They will particularly monitor Logan, the veteran coming off a serious left lat injury last season with the Indians.
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Logan said he's under no restrictions this spring.
"I'm champing at the bit to get out there," the veteran southpaw said. "I feel like I really haven't skipped a beat, but it's easy to say that prior. … I feel like injury aside, it's like riding a bike. Everything is crisp and there. I'm hoping to hit 90 [mph], which would be good for right now."
If the six relievers debuting Thursday and Friday all make it to Opening Day in full heath, it would leave two spots up for grabs. Besides traditional relief candidates like non-roster invitee J.J. Hoover, there also could be some spillover from the race for the starting rotation.
As for the relievers who pitched against Arizona, Knebel surrendered a run but worked in a series of curveballs, while Hader and Albers each worked a hitless inning. Hader struck out a pair of batters.
"There's a lot of depth there, obviously a lot of experience with Albers and Boone," Barnes said. "We're looking forward to gelling. That's one of the good things we've had since I've been here. Having an understanding of who might be in that group is a good thing."

Yelich gets first look in right
Christian Yelich made his first start as the Brewers' right fielder against the D-backs on Thursday. Brewers manager Craig Counsell has said he expects Yelich to primarily play left field, where he won a Gold Glove Award in 2014, but expanding his possibilities to right could help the Brewers spread at-bats among their stable of outfielders during the regular season.
"It's just a different viewpoint," Counsell said. "It will feel weird today, and then I would guess after today it will feel comfortable pretty quickly. He's just a very good defensive outfielder."
Yelich went untested in five innings in the field on Thursday but showed his skills in left on opening day of Cactus League play.
"The first ball that was hit this spring, he made a really nice play and we never talked about it actually," said Counsell, referring to Yelich's running catch of an Ian Happ drive toward the left-field corner at Maryvale. "A very difficult play. It was a quick sign of like, 'This is a really good defender.'"
Injury update
Jesus Aguilar was a late replacement on the starting lineup on Thursday for first baseman Eric Thames, who was scratched with a stiff back. Counsell said the switch was precautionary, and Thames is not expected to miss much time.
Last call
Counsell spoke Thursday morning about the benefits of having two left-handed relievers in Hader and Logan. While nothing is set at this early stage of Spring Training, it was another hint that lefty Brent Suter has a good chance to win one of the openings in the starting rotation. Counsell has said only that Suter has a "leg up" on a spot somewhere on the team based on his performance over the past two seasons.

Up next
Junior Guerra gets the start against the Mariners at 2:05 p.m. CT on Friday before Barnes, Jeffress and Logan take the hill for the Brewers. The game will be available through an exclusive audio webcast on MLB.com. Fans should consider arriving early, since their tickets will get them into a 10 a.m. MT "B" game between the Brewers and Angels, with Shohei Ohtani scheduled to pitch for Los Angeles.