The Tigers had relative success two years ago on a low-risk deal with a reliever in his second season back from elbow surgery. Joba Chamberlain became the Tigers' setup man in 2014, two years after his surgery, and played an underrated role in Detroit's fourth consecutive division title.
Parnell had a longer stretch of success, racking up three seasons of 60-plus appearances in a four-year span, before his elbow gave out. He pitched 301 1/3 innings over 292 Major League appearances from 2009 through 2013, posting a 3.52 ERA and 3.22 FIP while averaging 8.2 strikeouts per nine innings and a 2.44 strikeout-to-walk ratio. His fastball averaged at least 94.5 mph in every season during that stretch, according to Fangraphs.com.
With surgery in 2014, not only was Parnell's career stalled, his bullpen spot was open for others to take. He returned last June to make 30 appearances the rest of the year, but gave up 17 earned runs on 30 hits over 24 innings with more walks (17) than strikeouts (13).
Opponents hit Parnell's fastball for a .349 BABIP on the season, according to STATS, and he struggled to get swings and misses. Within those struggles, however, came a slow improvement in his fastball, from 92.23 mph in June to 96 mph in September, according to brooksbaseball.net.
The Tigers had been eyeing free-agent relievers since the holidays, hoping to find bargains close to Spring Training. With the 40-man roster full, however, Detroit did not want to give a guaranteed Major League contract and have to give up a prospect to make room. With Spring Training workouts beginning across the Majors this weekend, the lingering relief market began to move in recent days.
The Tigers worked out another former Major League pitcher Thursday, bringing in former Astros starter Lucas Harrell to throw on the back fields at Tigertown. However, Parnell's deal could conclude the Tigers' non-roster invites.
Jason Beck is a reporter for MLB.com. Read Beck's Blog, follow him on Twitter @beckjason and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.