Caissie (lumbar stress reaction) heads to IL, effectively ending rookie season

MIAMI -- The Marlins placed rookie outfielder Owen Caissie on the 10-day injured list with a lumbar stress reaction ahead of Sunday’s finale against the Dodgers at loanDepot park, essentially ending his 2026 season.

According to manager Clayton McCullough, Caissie told him that he felt pain down to his right hamstring running the bases, so Esteury Ruiz pinch-hit for Caissie in the third inning of Saturday’s 4-3 win.

Caissie had recently been dealing with low back discomfort and underwent a CT scan that revealed a fracture that will take some time to heal.

“Just kind of -- not numb, but just felt like weak -- and my back's been hurting,” Caissie said before the IL announcement. “In my career, yeah, I have [dealt with hamstring issues]. But this is different. This is not like a pull or anything like that.”

This marks the second time Caissie has landed on the IL this season, as he missed nearly a month with a right calf strain. Since his return on Aug. 1, Caissie has hit .164/.262/.274 with two doubles, two homers, eight RBIs, nine walks and 27 strikeouts in 28 games.

During this stretch, Caissie also dealt with neck spasms he experienced in Kansas City that kept him out for a few days

“Maybe I just tried too hard when I came back,” Caissie said. “I don't know. Last couple games felt a lot better, but I've never really done that before, like rehab, come back. I guess I know what to expect if I get hurt again. I guess I was trying to do too much and impact the team rather than just really play my game. But just the way it goes.”

Overall in his first full Major League season, the left-handed-hitting Caissie batted .220/.288/.412 with 14 doubles, 14 homers and 58 RBIs in 108 games. Despite the missed time and highs and lows, Caissie ranked fourth in home runs and fifth in RBIs among players on the active roster.

According to Baseball Savant, Caissie showcased above-average speed (28.3 mph, 75th percentile) and arm strength (89.3 mph, 82nd percentile) but poor range (-7 outs above average, sixth percentile) and swing and miss (37.3% strikeout rate, first percentile; 35.6% whiff rate, third percentile). His raw power was as advertised in terms of launch-angle sweet spot percentage (42.6%, 100th percentile) and barrel percentage (14.2%, 92nd percentile).

Caissie, who turned 24 on July 8, was the centerpiece in the return package for Edward Cabrera as Miami traded some starting pitching over the offseason to acquire MLB-ready or near-MLB-ready bats. After competing in the World Baseball Classic for Canada, Caissie made the Marlins’ Opening Day roster and primarily platooned when southpaws took the mound.

McCullough said he and Caissie spoke Saturday to assess his rookie season.

“I think it's been a very important and pivotal year for Owen,” McCullough said. “I think he can take away that there are just a lot of things that he did, and most young players don't appreciate until they're here. One, he mentioned defense and how important that really is, and he knew he needed to get better, and he still needs to get better. But he did. Kind of the midway point in the year until now, a lot of things under the hood that we believe will allow Owen to be a good defender. He's improved on his reactions. He runs fast enough to be a good outfielder. So he's very self-aware of that.

“And then offensively, that there's just no days off up here. Every arm you face – it's a real challenge. And so, buttoning up your game-planning and your approach that when you were going well, what led to that success, and then in times when you struggle, what is probably leading to those struggles. So, I think from that, Owen has gained a lot and learned a lot about himself. What he showed this year, why we like Owen as a player, he had a good stretch, we saw the power. We saw someone that can walk some, and a young player that we believe can improve on the defensive side of things.

“I told him he's handled having to get pinch-hit for and get taken out for defense. He's handled it very well. As the year's gone on, he's grown as a professional, because it's not easy to be able to take that on. So for me, it's been a positive year, and I say that because I think Owen right now looks in the mirror and is very aware of what he needs to do to be able to get better and continue to carve out a meaningful role with us.”