The transition to the National League, however, wasn't a smooth one, as Chen finished 5-5 with a 4.96 ERA in 22 starts. The 31-year-old missed about two months -- from July 20-Sept. 19 -- with a left elbow sprain and finished with 123 1/3 innings.
Before the season ended, Chen did make three promising starts. His fastball showed life, and he struck out 11 in his final 13 1/3 innings.
"I think at the end of the season, you saw a healthy Chen," president of baseball operations Michael Hill said. "We saw a pitcher closer to the one we saw in Baltimore, with the life and finish to his pitches. That's what we anticipated."
During his tenure with the Orioles, Chen was a consistent innings-eater, throwing at least 185 2/3 in three of his four seasons. He impressed with ERAs of 3.54 in 2014 and 3.34 in '15, and the Marlins signed Chen to match at the top of the rotation with Jose Fernandez.
The death of Fernandez has increased the importance of Chen doing his part to solidify the rotation.
Chen actually was the Opening Day starter this year, but that decision was made because Fernandez was on an innings plan.
Not overpowering, Chen relies on pin-point command. But his season never got on track.
Normally tough on left-handed hitters, that trend reversed off Chen. Left-handers batted .325 with a .353 on-base percentage off him after going .223/.250 in '15.
Chen's strikeouts per nine innings (7.30) were slightly up from a year ago (7.20), but his home runs per nine innings (1.61) were a career high.
How effective some of his pitches were also is telling. According to Baseball Savant, off Chen's two-seam fastball, batters hit .410 (34-for-83) with nine doubles, a triple and six home runs. Off the same pitch in 2015, they were 52-for-155 (.335) with nine doubles and 10 homers.
Against Chen's four-seam baseball -- the pitch he throws most often -- opponents were 51-for-207 (.246) with 10 homers. A year ago in Baltimore, they hit .231 (76-for-329) off that pitch.
At what point to replace Chen also is tracked. From pitches 76-90, batters are 232. But from 91-105, it jumps to .400. That explains why in his 22 starts, just three lasted at least seven innings.
"I feel like next year will be a better year for him, from the standpoint of knowing the league, knowing his teammates," manager Don Mattingly said. "For us, too, knowing him a little better, knowing when to pull the trigger with him, and seeing how his games go. So, for me, it will help make some better decisions with him."