To be fair, that is glossing over much of the struggle. For years, Henderson slogged through the Minors, a 26th-round Draft pick who didn't advance beyond Class A ball until he was 24 years old. It took three organizations, one shoulder surgery and almost a full decade for Henderson to make the Majors, which is when things more rightfully "took off."
At age 29, Henderson broke through, generating enough velocity out of his 6-foot-5 frame to strike out more than a batter and a half per inning in Milwaukee. By age 30, Henderson was the Brewers' closer, saving 28 games with a 2.70 ERA. Then barely a year later, he was back out of the Majors, undergoing a second shoulder surgery that robbed him of the entire 2015 big league season.
The Brewers stuck with Henderson, letting him rehab last summer at his own pace in the Minors. But results came sporadically. Toward the end of the season, Henderson says, his velocity was peaking at 95 mph -- not consistently, and certainly not the 98 mph he hit on occasion prior to surgery, but it was enough for optimism. Still, Henderson didn't know what the future might hold when the year ended, and he became free to sign anywhere, until the Mets emailed his agent the exact minute free agency began.
"I had no idea what to expect, especially coming off basically two years out of the big leagues," Henderson said. "It was pretty awesome. I didn't know whether I had to go through independent ball, I didn't know whether I was going to have offers -- I had no idea coming off of what I did. I'm sure the scouting reports last year were up and down. But it was definitely welcome."
That's not to say Henderson's struggle is complete. Mets manager Terry Collins said Saturday not only that he considers five pitchers -- Jeurys Familia, Addison Reed, Antonio Bastardo, Jerry Blevins and Hansel Robles -- locks for the bullpen, but also that incumbents Erik Goeddel and Logan Verrett will receive long looks for the final two spots. There is not much room then for someone like Henderson, whom the Mets can send to Triple-A Las Vegas without penalty.
But Collins also spent time gushing about the former closer who, at age 33, may be the only non-roster invitee to Mets camp with a legitimate chance to make the team.
"His history is very intriguing," Collins said. "I know he's a couple years out of surgery now, which we're hoping makes a big difference. I saw him in Milwaukee and he was very, very good. I'm just hoping we can catch lightning in a bottle."