The shoulder may have been an issue for Tillman throughout the 2017 campaign as he finished 1-7 with a 7.84 ERA in 24 appearances. According to FanGraphs, his 6.93 FIP was the highest among pitchers who logged at least 90 innings.
Beginning in August, Tillman shuttled between the rotation and the bullpen. Orioles manager Buck Showalter questioned whether the shoulder injury factored into the pitcher's poor performance.
"What would the indicators be?" Showalter said to reporters. "He's throwing the ball harder than he has in the last two or three years. He's throwing the ball 92-94 [mph] last night."
Showalter's assessment was a little off the mark, though. According to Brooks Baseball, Tillman's fastball averaged 91.24 mph, and his sinker clocked in at 90.89 mph. He averaged 92.90 and 92.74 mph on the two pitches, respectively, in 2016.
Pitching with an injury would help explain why a pitcher who had a career 4.13 ERA and a 4.45 FIP, per Baseball Reference, became one of the worst starters in baseball. Tillman also walked 4.9 batters per nine innings in 2017, compared to 3.2 from 2009 to 2016.
MASNsports.com's Roch Kubatko questioned whether Tillman would want to stay in Baltimore after such a rough season.
"It makes no sense on the surface for a pitcher attempting to reestablish his value on the market to reside in the American League East and call Camden Yards home," Kubatko wrote. "But I've also heard about the lure of being in an organization that already knows him and likely would exhibit more patience if he gets off to a slow start in spring training."
Tillman could be a solid bounce-back candidate in 2018. If his shoulder was bothering him, then he has had an entire offseason to rest and get back to 100 percent. The opportunity to pitch his way to a bigger contract will also be a strong incentive.
Over his career, Tillman has been a mid-rotation starter, so expecting him to pitch like an ace in 2018 is unrealistic. Should he return to his pre-2017 self, though, he'll be a solid value signing for the Orioles.