The Tigers found the offensive upgrade they needed and broke their trend of one-year contracts to do it. On Tuesday, they signed outfielder Robbie Grossman to a two-year, $10 million contract.

The deal includes up to $500,000 each season in performance bonuses based on playing time -- $250,000 at 500 and 550 plate appearances, according to a source.

The deal, while not a huge signing, is a milepost for the Tigers in their rebuild. Detroit hasn’t signed a free agent to a multi-year contract since the offseason of 2015-16, when it signed Jordan Zimmermann and Justin Upton to long-term contracts along with Mike Pelfrey and Mark Lowe to two-year deals in Al Avila’s first offseason as general manager. By the end of 2017, all but Zimmermann were gone, and the Tigers were all-in on their rebuilding effort.

All of the Tigers’ offseason dealings since then had been one-year contracts as Detroit focused more on the farm system. The Tigers were expected to look for similar deals as the offseason unfolded this winter; they did so on the pitching side two weeks ago with a one-year deal for right-hander José Ureña. Avila had warned last month about signing a multi-year deal they might have to unload later. Ultimately, the need to add a veteran bat and plate discipline to a young free-swinging lineup made Detroit’s front office more flexible.

“Robbie is a proven Major League hitter and will bring consistent, competitive at-bats to our lineup,” Avila said in a release. “His name quickly came up when our front office began planning potential offseason additions, and all of us are looking forward to having his veteran presence both on the field and in the clubhouse.”

The 31-year-old Grossman has been known for his on-base acumen for most of his eight-year Major League career, posting a .350 on-base percentage despite a .252 career batting average. Both waned a bit last year in Oakland, but he atoned for it with an uptick in power, hitting eight home runs and 12 doubles in 51 games for a career-best .482 slugging percentage. Much of that came from pulling the ball more often; his 17 percent rise in pull percentage was second-largest among qualified MLB hitters, according to Statcast.

Grossman’s 130 OPS+ was also the best of his career.

Grossman also has a background with new Tigers manager A.J. Hinch, who managed him in Houston in 2015. Grossman spent his first three seasons with the Astros, followed by three seasons in Minnesota, before spending the last two years with the A’s. Hinch’s presence is believed to be a big factor in swaying Grossman to Detroit.

“I’ve been fortunate to play for some great franchises during my career, and I couldn’t be happier to add the Tigers to that list,” said Grossman. “I’ve been in Detroit a number of times as a visiting player, and know how passionate the city and its fans are for Tigers baseball. I’m very excited to get to work with my coaches and teammates, and help bring winning baseball back to the Motor City.”

Grossman has one home run in 83 career at-bats at Comerica Park, but he also has five doubles and one triple there for a .289 batting average and a .791 OPS.

The Tigers had been checking around the free-agent outfield market as the offseason unfolded, including Adam Duvall and Nomar Mazara. Grossman doesn’t have their track record of power, but he has a much stronger on-base rate and lower strikeout clip, two aspects Hinch badly wants to improve in Detroit. The Tigers led the league in strikeouts over the last two seasons combined.

One American League evaluator described Grossman as a “solid guy to sign,” even with the two-year commitment.

“Not splashy,” the source described the signing, “but should help win games.”

Grossman is a switch-hitter with a relatively small difference in career splits against left- and right-handed pitching, though he has primarily been used against righties the last two years. He’s expected to be an everyday player in Detroit, which could push Christin Stewart into a competition with Victor Reyes, Daz Cameron and others for playing time in the other outfield corner. With Rule 5 Draft pick Akil Baddoo expected to make the roster as an extra outfielder, the Tigers could have a tight competition for outfielders simply to make the roster.

One such contestant could be out. To make room for Grossman on the 40-man roster, Detroit designated for assignment Troy Stokes Jr. Stokes was one of the bright spots of Tigers camp during an abbreviated Spring Training but missed Summer Camp and the 2020 season with a fractured hand. He tweeted earlier Tuesday that was ready and excited for Spring Training. He could still go to camp as a non-roster invite if he isn’t claimed on waivers in the coming days.