Rockies ship starter Sean Sullivan to Triple-A

Sullivan was lit up for six runs over 5 2/3 innings in a loss against the Giants on Saturday. They’ll now swap him out for a fresh bullpen arm for Sunday’s series finale at Coors Field. The 23-year-old left-hander will continue to hone his craft at the Triple-A level until his services are needed once more.

The Giants hung four runs on Sullivan in the opening frame on a walk and four hits. Two more hits in the second scored a fifth run. Bryce Eldridge then took him deep for a solo homer in the third. Sullivan would give the Rockies two scoreless frames, leaving with two outs in the sixth. He allowed 12 hits in all and walked two while collecting four strikeouts. The 23-year-old left-hander ends the day with an 8.87 ERA, 2.01 WHIP, and a 16/11 K/BB ratio across 22 1/3 innings. He’s currently lined up for a start against the Giants in San Francisco on Thursday.

Sullivan is up with Tomoyuki Sugano being placed on the injured list with back spasms, and the 23-year-old will make a start against the Giants on Sunday. If that goes relatively well — and even if it doesn’t, it’s the Rockies — there’s a good chance Sullivan will make another start with Sugano unavailable until after the break.

It’ll be rookie Sean Sullivan drawing the starting assignment at Coors Field in his place. The 36-year-old veteran has been dealing with a finger issue since his previous outing against the Twins last week, but it’s a back-related issue that will keep him from taking the ball this weekend. It sounds like this could become an injured list situation if he’s not ready to pitch in a couple days.

Sullivan has made four starts for the Rockies with an 8.64 ERA. At least he struck out five in this one after entering the night with seven strikeouts in 12 innings. One would think he’d be a leading candidate to be demoted with Tanner Gordon returning Tuesday.

Sullivan surrendered a run in the first inning on a walk and a triple. He then gave up another in the second on two more walks and a hit. Wilyer Abreu then took him deep for a solo homer in the fifth. Sullivan’s day would be done after five frames at 94 pitches. He struck out three. The 23-year-old left-hander could have his spot in the rotation taken by Tanner Gordon (hip), who is set to make one more rehab start for Triple-A Albuquerque on Wednesday. One more start for Sullivan would come Monday against the Marlins in Colorado.

This was an awful outing for Sullivan. In just his second start of the season, the young left-hander watched the Cubs hang a seven-spot on him in the second inning. The first five batters he faced all reached base and came around to score and then after recording one out, he allowed three more hits in a row. His fastball sat just below 90 mph and he shouldn’t be considered an option in even the deepest of leagues.

The quick hook was a product of Sullivan feeling ill during the outing. Still, he was effective while averaging just 87.6 mph with his fastball. He was at 89.0 mph in his 11 starts in Triple-A before getting the call on Friday. Odds are that he’ll head back to Albuquerque for now.

The 23-year-old hurler will start for the Rockies on Friday night against the Athletics in West Sacramento in what will be his MLB debut. Sullivan made 11 starts at the Triple-A level this season, posting an unsightly 5.60 ERA, 1.55 WHIP and a 50/19 K/BB ratio over 54 2/3 innings. He can be ignored for fantasy purposes.

No major surprises among this batch of cuts, though Sean Sullivan showed out well during Cactus League play and likely put himself in a position to earn his first promotion to the big leagues at some point in 2026 when the Rockies need another starter.