PORT CHARLOTTE, Fla. -- Devin Smeltzer knew something was off when he reared back for a pitch, really let it rip, looked up at the scoreboard and saw the radar gun flash 84 mph.

That was April 24, 2021, the only appearance he made with the Twins last season. Nearly a year later, at the end of a confusing, drawn-out injury journey, Smeltzer capped a nearly flawless Spring Training with four scoreless innings in the Twins' 8-2 victory over the Rays at Charlotte Sports Park on Saturday, putting a bow on a healthy spring in which he feels he has done enough to make his second Opening Day roster.

"I've controlled everything I can," Smeltzer said. "I left it all out there today. My goal going into the spring was to make it so the decision was going to be difficult. I hopefully left them an easy choice to put me back on the roster. I've controlled everything I can."

Smeltzer "couldn't hit the broad side of a barn" last Spring Training, when he lost his command because he lost feeling in the last three fingers of his pitching hand, he said. He worked his way back and made that one appearance for the Twins against the Pirates in April, after which it was clear to him that something still wasn't right.

When the scans came back clean, Smeltzer started rehabbing with the Twins' Rookie-level club in Fort Myers and built up to his penultimate rehab start in June, when he dropped to his knees in pain during a pregame bullpen session. It proved to be a herniated disc in his neck, requiring an ambulance ride to the hospital. Once he calmed down, though, there was relief in knowing that he hadn't been crazy; something really had been wrong.

To top it all off, Smeltzer also dealt with some long-term side effects that flared up from his radiation and chemotherapy treatments from his childhood battle with rhabdomyosarcoma, a soft tissue cancer.

Because of the hernia, Smeltzer had to totally shut down for four weeks -- no activity whatsoever, to the point where Twins staffers had to chastise him for trying to walk on a treadmill. He had to buy and restore a 1972 Chevrolet Nova, he said, to fill the time.

When he was allowed to throw again, he slowly built back up, pitching into October, feeling his old stuff return. He had a healthy, normal offseason, and that stuff was clearly back, with radar gun readings in the 90s once again on Saturday against the Rays.

After allowing two hits and two walks against a lineup featuring mostly Tampa Bay big leaguers, Smeltzer will finish Grapefruit League play with five hits allowed, eight strikeouts and two walks in 11 scoreless frames.

"The stats speak for themselves," Smeltzer said. "I'm commanding the ball again. Velo is there. Stuff is there. Mentally, I've got the fire and rage back. I can't have any regrets about work. It is what it is at this point."

The Twins need built-up arms for their Opening Day bullpen, which could include five or six pitchers who can contribute multiple innings. Though Smeltzer has built up as a starter this spring, manager Rocco Baldelli has noted that all of Minnesota's pitchers may need to be ready to provide versatility in April, when the rotation won't be fully built up.

Smeltzer and Danny Coulombe -- both non-roster pitchers -- lead the stretched-out lefties remaining in camp. Smeltzer has had success in such a versatile role, posting a 4.26 ERA and 1.26 WHIP in a spot starting and long relief role across parts of three seasons with the Twins.

Whether he has earned a spot on the Twins' roster for Opening Day or later in the season, Smeltzer is confident he's all the way back. The rest is out of his hands.

"He’s done really as much as someone can do in a camp," Baldelli said. "I think we’re seeing the best version of him right now. He’s made the conversation really challenging for us, because it’s another really good arm that we have to consider right now. But again, his camp was highly successful."

"I'm healthy and going to compete no matter where I'm at," Smeltzer said. "I'll be back."