MLB mock draft: 2025 draft week update

Kicking off a week of comprehensive 2025 MLB Draft coverage at Fish On First, here is an updated mock draft that goes through the entire first round as well as prospect promotion incentive picks, free agent compensation picks and Competitive Balance Round A.

The biggest riser when comparing this to March's mock is LSU's Kade Anderson, who I previously forecasted to fall outside of the first round. The biggest faller is Tennessee's Dean Curley (previously mocked to go No. 10).

The seventh and 43rd overall selections belong to the Miami Marlins. I have them using both picks on California prep prospects: right-hander Seth Hernandez from Corona High School and shortstop Cooper Flemming from Aliso Niguel High School. 

Seth Hernandez

Early in the draft process, Hernandez separated himself as the top prep pitching prospect in the 2025 class. At 6’4” and 190 pounds, he has the ideal pitching frame with room to fill it out with more muscle.

Hernandez has a four-pitch mix. His fastball sits 96-98 mph and was clocked at 100 mph last summer. It has an above-average spin rate and explodes out of his hand. The changeup might be Hernandez’s best pitch. His curveball has a true 12-6 break and he also uses a sharp slider.

The high-ceiling right-hander has good control and fills up the strike zone, but he will need to fine-tune the command of his secondary pitches.

Hernandez is signed to play college baseball at Vanderbilt University.

Cooper Flemming 

Flemming has risen up public big boards following strong performances in the spring. A lanky teenager standing at 6'3", he has shown an impressive ability to make consistent contact, posting a 89% contact rate in games where Trackman data was collected. He's been posting exit velocities north of 100 mph already and it's reasonable to project a significant increase in that area as he matures.

With a smooth swing and quiet load from the left side, Flemming is able to stay on time and on plane with pitches while generating good bat speed.  

In the field, Flemming has the tools to stick at short with a very strong arm and quick feet. Third base would be his potential fallback position. He is an average to above-average runner on the bases.

Another Vandy commit, Flemming will require a seven-figure bonus to forgo college, but he should be willing to settle for less than this pick's $2,276,700 slot value.