DETROIT – The start of spring training is less than a month away, but there are still plenty of free agents signed around Major League Baseball.

Bryce Harper and Manny Machado have headlined the quiet offseason, but there are several players with lower profiles still trying to find a home for 2019.

The Detroit Tigers have made a handful of minor moves, signing starting pitchers Matt Moore and Tyson Ross and infielder Jordy Mercer. The Tigers aren't likely to make a big splash between now and Opening Day, but there are plenty of free agents who could still be solid short-term investments.

The Tigers appear to be satisfied with their starting pitching and lineup at this point -- you can read more on those in the links below -- so here are five relief pitchers that should be on their radar.

LHP Justin Wilson

2018 stats: 71 games, 52.4 innings pitched, 69 strikeouts, 3.64 FIP, 1.43 WHIP.

Justin Wilson pitches in the 12th inning against the Colorado Rockies during the National League Wild Card Game at Wrigley Field on Oct. 2, 2018, in Chicago. (Stacy Revere/Getty Images)

Remember Justin Wilson? He worked out well for the Tigers during his last stint in Detroit, working his way into the closer's role and then becoming the main piece of the trade that brought Jeimer Candelario to town.

UPDATE: Justin Wilson reportedly signed a two-year deal with the New York Mets on Friday

Wilson rebounded nicely for the Cubs in 2018 after an awful end to 2017 that saw him post a WHIP over 2.0 in Chicago. He still allowed plenty of base runners and walked 5.4 batters per nine innings last season, but struck out 11.4 batters per nine innings and allowed fewer hits.

The 31-year-old has a power arm and makes up for his walk rate with dominant strikeout totals. He's never had a FIP higher than 3.64 in a season, so few relief pitchers have been more consistent since he burst onto the scene in 2013.

The Tigers could have a chance to land Wilson because of his prior success in Detroit and a reluctance by other teams to take on his walk rate.

Wilson would be a workforce left-hander in the Tigers bullpen and could once again be a trade chip at the deadline.

RHP Adam Warren

2018 stats: 47 games, 51.2 innings, 52 strikeouts, 3.94 FIP, 1.32 WHIP.

Adam Warren of the Seattle Mariners pitches against the Texas Rangers in the ninth inning to secure the 12-6 win at Safeco Field on Sept. 28, 2018, in Seattle. (Lindsey Wasson/Getty Images)

Adam Warren is a longtime New York Yankees reliever who's been overshadowed by Aroldis Chapman, Dellin Betances, David Robertson and Andrew Jones throughout his career.

Warren has been an asset for the Yankees, though, appearing in 246 games with a 3.18 ERA, 1.19 WHIP and eight strikeouts per nine innings.

Warren has done some of his best work in the last two seasons, averaging about a strikeout per inning in 93 appearances while posting a 3.45 FIP and 1.08 WHIP. His walk rate is manageable and he mostly keeps runners off the base paths.

He's a free agent in 2019 after making just over $3 million last season. At 31 years old, he could get a multiyear deal or sign a one-year contract to try to improve his stock for next offseason. The Tigers could use a steady veteran presence in the bullpen, and if Warren had a breakout season, he would be more trade bait.

RHP Greg Holland

2018 stats: 56 games, 46.1 innings, 47 strikeouts, 3.83 FIP, 1.62 WHIP.

Greg Holland of the Washington Nationals pitches in the ninth inning against the Miami Marlins at Nationals Park on Aug. 17, 2018, in Washington, DC. (Mitchell Layton/Getty Images)

One year after leading the league in saves -- while pitching for the Colorado Rockies, no less -- Greg Holland completely fell apart on the mound in St. Louis.

The longtime closer lost that spot with the Cardinals while allowing 22 walks and 28 runs in 25 innings. He was released in August and signed with the Washington Nationals.

He returned to his dominant form in Washington, allowing two runs and striking out 25 hitters in 21.1 innings.

Holland's career numbers, along with his dominance in 2017 and in the second half of 2018, suggest last year's slow start might have been an anomaly. He didn't sign with the Cardinals until March 31, just days before the start of the season. It's possible that put him behind and he didn't catch up until being released.

The Tigers aren't a playoff contender, so they're in the perfect position to take a chance on Holland being his usual self. If that comes to fruition, it could pay huge dividends, both for the young bullpen pitchers and at the trade deadline. If it doesn't work out, it won't cost the Tigers a chance at the postseason.

LHP Jake Diekman

2018 stats: 71 games, 53.1 innings, 66 strikeouts, 3.74 FIP, 1.50 WHIP.

Jake Diekman of the Arizona Diamondbacks throws in the seventh inning against the Colorado Rockies at Coors Field on Sept. 13, 2018, in Denver, Colorado. (Matthew Stockman/Getty Images)

Jake Diekman struggled late last season after being traded to the Arizona Diamondbacks on deadline day, but he put in three full years of solid work with the Texas Rangers beforehand.

Between the 2015 and 2018 trade deadlines, Diekman appeared in 150 games for the Rangers, striking out 140 batters in 124.1 innings while posting a 3.60 FIP and 1.21 WHIP.

He's been dominant against left-handed hitters in his career, holding them to a .638 OPS, but Diekman isn't a liability against right-handers, either. Righties have just a .680 OPS against Diekman in almost twice as many at-bats as lefties.

Diekman has been traded at the deadline twice in the last four seasons because lefty specialists are always valuable additions to teams hoping to make late playoff pushes. Even though 2018 was a bit of a down year, Diekman has always done his best work in the American League, and the Tigers could try to capitalize on that.

RHP Shawn Kelley

2018 stats: 54 games, 49 innings, 50 strikeouts, 3.71 FIP, 0.90 WHIP.

Shawn Kelley of the Oakland Athletics throws a pitch against the New York Yankees during the fifth inning in the American League Wild Card Game at Yankee Stadium on Oct. 3, 2018, in the Bronx borough of New York City. (Elsa/Getty Images)

Other than an outlier season in 2017, Shawn Kelley has been one of the more reliable relievers in baseball among the current free agents.

Coming off a season in which he averaged about a strikeout per inning and posted a ridiculously low WHIP, Kelley should have plenty of options on the free agent market, so this is probably a long shot for the Tigers.

But with spring training less than a month away, who knows where Kelley will land?

He emerged as a high-end reliever in 2015 and 2016 when he struck out 11.8 batters per nine innings while posting a 2.78 FIP and 0.99 WHIP. He had a low walk rate, didn't give up many hits and kept the ball in the park.

Kelley will turn 35 years old in April, so he's not likely to get many long-term contract offers. Plenty of teams have room for a strike-throwing setup man with good underlying numbers, but the Tigers should still give him a look.

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