SEATTLE -- Hisashi Iwakuma, who was shut down since early February, will throw off the mound for the first time on Wednesday. The All-Star right-hander is scheduled for a 30-pitch bullpen session, manager Lloyd McClendon said Tuesday.
Iwakuma, 32, has been sidelined since just before Spring Training opened after spraining a tendon in his right middle finger while catching it in a netting during a throwing session in Los Angeles.
The Japanese star is eligible to come off the 15-day disabled list, but he'll need to build up his arm strength with several bullpen sessions and then a Minor League rehab stint, most likely with Triple-A Tacoma.
McClendon said Iwakuma is "probably a little ahead of schedule" and could move through the rehab process quicker than has been the case for 21-year-old prospect Taijuan Walker, who is scheduled to make his second Minor League rehab start this week for Double-A Jackson.
If Walker stays on a five-day schedule, he'll start Wednesday when the Generals open their home season against Chattanooga.
"We want to try to keep him in warm weather as long as we can," said McClendon, who hopes to build Walker up to 80-85 pitches after he threw 72 for Class A High Desert on Friday. "This gives us an opportunity to move him to a higher level and still stay in a fairly decent climate."
Walker could be close to rejoining the Mariners after his next start, while Iwakuma still has several weeks before reaching that point. McClendon did note that Iwakuma normally is a very efficient pitcher and should be able to get deeper into early games without having worked up to as high of a pitch count, but he isn't committing to a time frame for Iwakuma's return.
"I think it's going to be a session-to-session thing, just like it was with Walker," McClendon said. "Traditionally, if you look at Kuma's history, he's been able to go through seven innings within a fair amount of pitches. He's a strike thrower. So if I had to guess, I'd think his progression will be a little faster. But having said that, we're still going to be very cautious with him."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.