JUPITER, Fla. -- Twenty-three months removed from game action, Marlins right-hander Zach Pop returned to the mound and fired a first-pitch 96.7 mph fastball for a strike on Wednesday night in a 4-4 tie with the Astros at Roger Dean Chevrolet Stadium.

Pop, who tossed a scoreless eighth inning on 21 pitches (11 strikes), last appeared in a game on April 6, 2019, for the Orioles' Double-A club. He underwent Tommy John surgery a month later.

"Warming up in the 'pen, it was nice and easy," Pop said during a Zoom call after the outing. "Kind of just felt like another day at the ballpark, [like] you're going to throw a side or something. And it didn't really hit me until I stepped on the game mound and I was like, 'Woah, this is a little bit different from the lives' or, 'This was a little bit different from what we're used to.'"

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Once part of the 2018 package the O's received from the Dodgers in exchange for Manny Machado, Pop was among Baltimore's Top 30 prospects before the procedure. He had compiled a 1.34 ERA, 0.91 WHIP and 9.0 strikeouts per nine innings over three Minor League seasons. Across 80 1/3 innings, the righty recorded eight saves, surrendered just one homer and posted a .173 average against in 57 appearances. In '18, Pop boasted a ground-ball rate of 61.9 percent.

Despite Pop's long absence from the game mound, that upside enticed the D-backs to select him in this past December's Rule 5 Draft. The Marlins then acquired Pop in a trade for a player to be named. Later in the offseason, Miami acquired Anthony Bass, Ross Detwiler, Dylan Floro, Adam Cimber and John Curtiss to fill out the bullpen. With that quintet joining returning arms like Yimi García, Richard Bleier and James Hoyt, how might Pop fit into the mix?

"He's got good stuff, we just haven't seen enough," Marlins manager Don Mattingly said during a Zoom call. "We'll let him keep going and get him back out there. Obviously, you don't take those [Rule 5 Draft] guys unless you like their stuff, what you think they could do. We'll just kind of let it play out, but he threw the ball pretty good. Like I said, first time out looked a little kind of all over the place, but you know the ball moves and he's got a good breaking ball."

Following a leadoff walk, Pop picked up a strikeout looking on a 95.3-mph two-seamer before inducing two weak grounders in his 2021 Grapefruit League debut. His first offering at 96.7 mph stood as his maximum velocity for the outing, as he averaged 95.2 mph with the heater. According to Statcast, the MLB average velocity for a right-hander on two-seamers was 93.2 mph in 2020. Pop mixed in 14 fastballs and seven sliders.

The 24-year-old reliever admitted he had to manage his excitement because adrenaline kicked in. With the COVID-19 pandemic canceling the 2020 Minor League season, Pop's timetable for a return was pushed back even further. So he threw indoor bullpen sessions back home in Canada, and then navigated an offseason of working out and building intensity. Throwing batting practice on the back fields this spring had nothing on the pressure to make pitches and record outs in a game setting.

"It felt like relief that I made it through the rehab process, and we're healthy, and a lot of positive stuff came from that," Pop said. "A lot of stuff that we could build towards in the future."