"And Charlie is getting ready to go out and face hitters and start his innings progression. If we have the opportunity to add those two before long, it really helps the arrow point north for the bullpen, which I think has already been a real positive."
The Mariners' bullpen was tied for the lowest ERA in the Majors at 2.37 heading into Wednesday's series finale with the Rays and had the lowest opponents' batting average (.178).
Benoit pitched five games early in the season, posting a 3.60 ERA before going on the 15-day disabled list on April 25 with right shoulder inflammation. But the shoulder had been nagging him much of the spring, and it appears the 38-year-old setup man may finally be free of that issue.
If Benoit has no issues coming out of Wednesday's work, he'll throw a simulated inning against some of the Mariners' bench players prior to Saturday night's game against the Angels. Dipoto said Benoit will not be asked to go on a Minor League rehab stint and instead will rejoin the club as soon as he's ready. The team opens a six-game road trip to Baltimore and Cincinnati on Tuesday.
Furbush is on a much slower path as he hasn't thrown in a game since last July after dealing with a slight rotator cuff tear. The Mariners hoped to have him back by the start of this season, but a setback in Spring Training slowed that return and he's just now gearing up with three straight bullpen sessions.
Dipoto said Furbush will next proceed to facing live hitters in a controlled batting-practice session in Tacoma, then would head to the club's facility in Peoria, Ariz., to start "a normal Spring Training innings progression."
That would mean building up his arm strength through a series of simulated games and then a half-dozen or more Minor League outings, which means in a best-case scenario he's looking at a mid-June return.
• Dipoto confirmed that top pitching prospect Edwin Diaz is being converted into a reliever at Double-A Jackson with the belief his top-end ceiling is higher out of the bullpen. Dipoto said Diaz threw 96-98 mph in his first relief inning for Jackson on Tuesday, a 1-2-3 eighth inning in a 3-2 victory over Birmingham.
"We felt he had the potential to be a Major League starter, but he has the potential to be an impact Major League reliever. And to me, one supersedes the other."
• Dipoto said lefty James Paxton will be limited to one inning in his Wednesday start for Triple-A Tacoma as part of an innings-control plan, then go back to his normal routine in his next outing in five days. The Mariner are pleased with Paxton's progress.
"He's been great," Dipoto said.