PEORIA, Ariz. -- There's no question that Edwin Diaz will be the Mariners' closer after his outstanding rookie season last year. But who will be setting up the young right-hander in the late innings? That remains a bit of a work in progress.
With former closer Steve Cishek not expected to be ready for the start of the season, as he works back from microfracture hip surgery, and fellow right-hander Shae Simmons -- acquired from the Braves in January -- temporarily shut down to rest a sore forearm, the setup roles for Seattle are still to be determined.
Manager Scott Servais says veterans Nick Vincent and Evan Scribner, and rookie Dan Altavilla, who was impressive in a September callup last year, are the logical candidates. Servais will also use lefty specialist Marc Rzepczynski when the situation calls for it, and he said right-hander Casey Fien, another free-agent signee, is in the mix as well.
"We've got some competition now with Cishek being out and Simmons having a little setback," Servais said. "I think how things play out, it will come right down to the end of camp and how those outings go. As you see the 'A' lineups play deeper into games, you're starting to fire all of those guys in against the heart of Major League orders, versus just getting Minor League players in the end of those games. You find out a little bit more."
Servais didn't rule out the idea of opening the year with eight relievers instead of the normal seven, which would mean being short a position player on the bench.
Zych to throw Wednesday
Right-handed reliever Tony Zych, working his way back from biceps surgery in October, will throw off a mound to hitters in a batting practice session for the first time this spring on Wednesday morning.
"It's just one step, but it's an important step," said Zych, the club's No. 14 prospect, per MLBPipeline.com, who is hoping to get into game mode by the start of the season in April.

The 26-year-old was on Seattle's Opening Day roster last year, and he went 1-0 with a 3.00 ERA in his first 10 outings, before going on the disabled list with shoulder issues that limited him to just two appearances the rest of the year.
Worth noting
• The Mariners' annual batch of humorous, promotional TV commercials will be released on Wednesday at 10 a.m. PT. They can be viewed on mariners.com.
• Vincent gave up a home run in the sixth in Tuesday's 7-6 win over the White Sox, and he has allowed a homer in each of his four relief outings this spring.
"He threw a pitch he typically wouldn't in that situation," Servais said. "He's working on a changeup to get that going against the lefties and left it up a little, and the guy put a good swing on it. But I thought after that, he threw the ball well. It's just one pitch here or there that's costing him right now."