3/2 - 3/8 Spring Training Prospect Notables

Leo De Vries, ATH, Baseball Focus #5

In his first big league camp as a member of the Athletics, Leo De Vries is off to a hot start. Although he has been hitting all spring, he finally parked one on Sunday, not once, but twice against the Dodgers including a grand slam as he finished the day with six runs batted in. In his 17 plate appearances on the week, his 1.284 OPS ranked fifth among qualified hitters as he added five more hits and a walk with two stolen bases for good measure. In 28 plate appearances across the entire spring, De Vries is up to a 1.044 OPS while slashing .385/.429/.615. As De Vries did in 2025, he is hitting better from the left-side of the plate as opposed to the right side. Seven of his ten total hits have come against right-handed pitchers and owns a 1.172 OPS as a left-handed hitter and just a .750 OPS as a right-handed hitter. After a strong 2025 in which De Vries performed well as a 19 year old in Double-A, there is a scenario in which De Vries debuts by the end of 2026. In a loaded crop of shortstop prospects, don’t forget about De Vries.

Henry Bolte, ATH

Another toolsy Athletics position player prospect, Henry Bolte led all qualified hitters in OPS this past week at a mark of 1.667 in 15 plate appearances. He went 8-13 on the week, posting a .615/.667/1.000 slash line with his first home run of the spring on Sunday against the Angels. He added two doubles and two walks as well. This has been the longest amount of run Bolte has gotten in big league camp with the A’s, and it has also been his best showing. In 29 plate appearances across the spring, he owns an 1.150 OPS with 12 hits, a mark that is tied for the spring training league lead. A 2022 second round draft pick out of high school, Bolte has spent three full seasons in the A’s system where he presents himself as a plus defender and runner with a risky hit tool. The development of his contact skills will be the difference in him being merely a late-game defensive replacement/pinch runner and an impact center fielder. He advanced as high as Triple-A in 2025 right before turning 22, but struck out 32.6% of the time so he’s likely to spend a lot more time there in 2026, but could certainly fill a hole on the Athletics roster if his name is called at some point.

Joshua Baez, STL

The 22 year old shortstop prospect for the Cardinals just missed the Baseball Focus top 50, but is very likely to find himself ranked upon the graduation of a number of current top prospects. Baez hit his first two home runs of the spring in consecutive days on Friday and Saturday. The first home run was a 436 foot shot at a 110.8 mph exit velocity while his second was off of Mets starter Kodai Senga that traveled 388 feet at 102.7 mph. He only got nine plate appearances on the week, but managed to go 3-6 with a walk. Baez advanced as high as Double-A in the Cardinals system last year where he hit 20 home runs and stole 54 bases between High-A and Double-A, showcasing his speed/power profile.

Quinn Mathews, STL

One of the top ranked pitching prospects in the Cardinals system, Quinn Mathews delivered an impressive outing on Thursday against the Pirates in which he struck out seven hitters in just 2.2 innings of work. He did give up two hits and an earned run via a home run, but didn’t issue any walks. Mathews featured a six pitch mix, but was most effective with his three highest used offerings - the fastball, changeup,, and slider. The three pitches combined returned a 54.5% whiff rate while it was a 44% whiff rate for the fastball, 57% on the changeup, and 67% on the slider. At 24 years old in 2025, Mathews was hopeful to join the Cardinals rotation at some point, but his command backed up at an alarming rate as he walked 17.5% of hitters he saw at Triple-A. The sample size in spring training thus far is still tough to project upon, but it’s worth noting he’s currently sporting a 24.2 K-BB% in seven total innings.

Jack Wenninger, NYM

Jack Wenninger is one of the emerging pitching prospects in the Mets system and just delivered his best outing of the spring on Saturday against the Cardinals. It was a rough showing in his prior outing as he walked five in just an inning and a third while allowing two earned runs to the Astros. Wenninger changed his fortunes on Saturday as it was three scoreless frames with five strikeouts, three hits, and zero walks. Wenninger was dominant with his changeup which he threw 31% of the time, returning a ridiculous 77.7% whiff rate. It played great off of his fastball which had a 38% whiff rate with 16 IVB and 11 HB at 96 mph compared to 4 IVB and 13 HB at 85 mph with the changeup. He mixed in a slider, sinker, and sweeper as well. In three spring training appearances thus far, Wenninger owns a 31.3% strikeout rate. The 23 year old right-hander spent the entirety of 2025 at Double-A where he posted a 2.92 ERA and a 26.4% strikeout rate across 135.2 innings.