DETROIT -- The Tigers don’t have many of their own free agents to worry about this offseason. But Elvin Rodriguez was about to become one of them.

Never mind that the 23-year-old has never pitched in the Majors, and hadn't pitched above Double-A Erie until he pitched two innings of relief for Triple-A Toledo in his final outing of the season. He was about to hit the open market with a chance to pick his potential path to the big leagues. One call from the Tigers changed the course.

“I knew that it might be a chance, a possibility for the team to put me on the 40-man roster, but I knew also that there was a chance for me to turn into a free agent,” Rodriguez said through a translator in a video conference with reporters from his home in San Pedro de Macorís, Dominican Republic. “But to be honest, yeah, it caught me by surprise. But also to be honest, that’s one of the things I’ve been working for the whole season.”

For most prospects, the decision over whether teams add them to the 40-man roster is about protecting them from the Rule 5 Draft, where other clubs can select them with the idea of keeping them on their 26-man active roster for the next season. Rodriguez was in a different situation because had more time in the Minor Leagues, enough that he could’ve become a six-year Minor League free agent. Had that happened, he would’ve been free to sign with any organization, who would’ve had his full rights without having to keep him on their active roster. The chances of Detroit losing him in free agency would’ve been overwhelmingly high.

Rodriguez was a day away from the open market when the Tigers added him to their 40-man roster on Sunday.

He wasn’t the only one surprised by the move, at least by the timing.

Normally, a 4-6 record and a 5.68 ERA doesn’t suggest a prospect needing to be protected. Rodriguez was on MLB Pipeline’s Tigers top 30 prospect list in 2020, but he dropped off going into 2021. Go beyond the basic stats, however, and Rodriguez had some factors in his favor.

Rodriguez pitched at the start of the season like a prospect on the rise, allowing just two hits over 14 1/3 scoreless innings in his first three starts for Erie. He walked four batters, struck out 19 and held opponents to 2-for-45. He had some good fortune, including 10 fly-ball outs over 5 1/3 hitless innings in his third start on May 18 against Binghamton, but was pitching strong.

Those fly balls turned against him when he faced the same club five days later and allowed a pair of home runs, but he still finished with five innings of three-run ball in a victory. He then had the bigger fortune of becoming a father.

“When I got back to the field, I felt it was a little bit different for me,” Rodriguez said. “But it was a big motivation to have a baby and something to fight for.”

What was expected to be a brief absence for paternity leave at the end of May lasted nearly three weeks, a hiatus due in part to COVID protocols and travel. He pitched three innings in his return in mid-June, was hit for four first-inning runs six days later, and embarked on a roller-coaster summer in which he struggled to find pitching consistency.

Rodriguez pitched 6 1/3 scoreless innings in an Aug. 12 start, then gave up seven runs and three homers the next time out. He remained consistent in throwing strikes and getting fly balls; he recorded more than five ground balls in just two starts.

“Numbers do not define everything,” Rodriguez said. “I think the numbers could have been better. There’s always going to be a season with good numbers, and there’s going to be a season in which the numbers are not that good. But obviously, if you are competing and doing your best and helping the team to win, in the end, that’s what matters.”

Rodriguez, acquired from the Angels in the Justin Upton trade in 2017, is not an overpowering pitcher; his fastball can approach 95-96 mph but averages in the lower 90s. He makes it more effective with a breaking ball and changeup.

“My breaking ball has improved a lot,” Rodriguez said. “It has a bigger spin, and it’s a little bit faster reaching the catcher’s mitt. I added a slider to my repertoire and it has helped me a lot. Obviously I know that getting my fastball better and getting my changeup even better will help me a lot.”

It’s not the type of arsenal that wows an evaluator, but he made it work for 83 strikeouts over 77 2/3 innings, good for a 9.6 K/9 ratio that is easily the highest in any full season of his career. For the Tigers, adding Rodriguez to the roster in an offseason when spots are going to be tight was a bit of an upside play to see if he can build on it.