2) Mark Vientos
Mark Vientos looked like he could be one of the top sluggers at third base after a breakout 2024 season. Last season, he slashed .266/.322/.516 with a .356 wOBA and 133 wRC+ in 454 plate appearances. Sure, he struck out nearly 30% of the time with a 29.7% K% and had a sub-par 7.3% walk rate, but he smacked 27 long balls, and his .249 isolated slugging percentage led all NL third basemen with at least 300 plate appearances. The only 3B in the entire league who surpassed Vientos was Cleveland Guardians’ Jose Ramirez.
But 2025 has been a struggle for Vientos. He’s only batting .232/.299/.375 through his first 187 trips to the plate. His isolated slugging percentage has dropped by just over one hundred points, down to .143. The only positives are his walk rate is up to 8.6%, and he’s significantly cut down on strikeouts, with a 21.4% K%. However, that drop in K% has come at the cost of his barrel rate, going from 14.1% in 2024 to just 6.9% this year. Vientos clocks in with a .298 wOBA and 92 wRC+.
Unlike Acuna, Vientos doesn’t at least provide value on the bases or as a defender. Both his -7 defensive runs saved and -6 outs above average are the fewest of any NL 3B. The only third basemen with less DRS are Luis Rengifo and Gio Urshela, and the only player with less OAA at the hot corner is Junior Caminero. He’s also in just the 22nd percentile of sprint speed.
There are currently 21 third basemen in the league with at least 150 plate appearances. Vientos has the sixth lowest WPA at -0.55 among those 21. He is also the only Mets player with zero fWAR in 100+ plate appearances. Vientos is not coming even close to replicating anything like his 2024, which is a bigger hindrance on the Mets’ lineup than anything Soto has done this season.
