SEATTLE -- General manager Jerry Dipoto has been sticking with his promise of staying relatively quiet this offseason, but that doesn’t mean the Mariners won’t make any more moves before pitchers and catchers report to Spring Training camp next month.

Dipoto and his staff have been keeping tabs all winter on potential bounce-back starting pitchers to add depth to their rotation and provide options should rookie prospect Justin Dunn not appear ready for the fifth-starter role this spring.

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Félix Hernández, Wade LeBlanc and Tommy Milone departed in free agency, but the Mariners already filled one spot with 29-year-old free agent Kendall Graveman, a two-time Opening Day starter for the A’s who missed part of 2018 and all of last season following Tommy John surgery.

Dipoto would like to bring in another low-risk, high-reward candidate to join the rotation mix with Marco Gonzales, Yusei Kikuchi, Justus Sheffield and Graveman, preferring a relatively young pitcher with upside who could be part of the longer-term plans.

The ideal candidate would have the versatility to pitch out of the bullpen in a swingman role should everyone stay healthy and Dunn be deemed ready from Day 1, though history shows that more than five starters are almost always required due to injuries and performance issues.

One of the Mariners’ targets came off the board this week when former Brewers right-hander Jimmy Nelson, a 30-year-old coming off shoulder problems, signed an incentive-laden deal with the Dodgers that guarantees him $1.25 million for 2020 with a $2 million option for ’21.

The Mariners have indicated some interest in a reunion with Taijuan Walker, who was released by the D-backs after missing almost all of the last two seasons with elbow problems. Walker fits the age profile and bounce-back potential the Mariners are seeking, and they certainly are familiar with the 27-year-old. He was drafted by Seattle in 2010 and went 22-22 with a 4.18 ERA in 65 outings (62 starts) from 2013-16 before being traded to Arizona in the Mitch Haniger/Jean Segura deal.

But Walker, who earned $5 million with the D-backs last season, surely is drawing interest from other clubs after finally getting healthy in time to throw one scoreless inning in Arizona’s season finale last September.

Dipoto doesn’t feel the need to sign a proven “innings eater” who can crank out 180-plus frames, given the team’s desire to leave an opening for Sheffield, Dunn and other youngsters to develop.

The Mariners experimented with using LeBlanc and Milone as long-inning relievers behind one-inning openers last season and could use whomever they sign in that role, or as an insurance policy for Dunn, who pitched at Double-A Arkansas last year before getting four short starts -- and 6 2/3 innings of work -- with the Mariners in September.

So a bounce-back candidate looking for the opportunity to build his arm -- and reputation -- back up after a tough season or two could be the perfect fit.

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Among the remaining free agents who could fill that type of role and are still 30 or younger, here are some potential candidates:

Walker: The former Mariner went 9-9 with a 3.49 ERA in 28 starts in 2017 after being dealt to the D-backs, but he made just four starts and totaled 14 innings over the past two seasons and then was non-tendered in November because of his elbow issue. But he’s still just 27 years old and could be an interesting candidate for any team if healthy.

Alex Wood: The lefty, who turns 29 on Sunday, had a 3.29 ERA from 2013-18 with the Braves and Dodgers, but made just seven starts and posted a 5.80 ERA with the Reds last year due to back problems.

Drew Smyly: Would the Mariners take another shot with Smyly, who never threw a regular-season pitch for them after after being acquired from the Rays? He hurt his elbow in the World Baseball Classic and required Tommy John surgery that wiped out his 2017 and ’18 seasons. Smyly went 4-7 with a 6.24 ERA in 25 outings (21 starts) with the Rangers and Phillies last season, but he is still just 30 and could be in line for a better season now that he’s a year removed from his rehab process.

Shelby Miller: Since he posted a 3.02 ERA in 33 starts as an All-Star with the Braves in 2015, things have gotten rough for the 29-year-old right-hander. A finger injury shortened his ’16 season with the D-backs and he had Tommy John surgery in ’17. Miller pitched poorly with Arizona and Texas since returning, including an 8.59 ERA in 44 innings with the Rangers last year while struggling with his command. But the 6-foot-3, 225-pounder still throws in the mid-90s and could be a factor with an extra year of recovery under his belt.

Matt Harvey: No bounce-back list is complete without the former Mets standout, who has been plagued by a series of injuries over the past four seasons. The 30-year-old had a decent year with the Reds in 2018 (7-7 with a 4.50 ERA in 24 starts) but was just 3-5 with a 7.09 ERA in 12 starts for the Angels last year before being released in midseason. Harvey signed a Minor League deal with the A’s in August and put up a 3.18 ERA in five Triple-A outings before asking for his release to become a free agent at season’s end.