The Chicago Cubs are not in any rush to get Mason McGwire, the son of Mark McGwire, to Major League Baseball. They are willing to let him develop as a prospect.
He is only 22 years old!
There are a lot of similarities between the 12-time MLB All-Star and his son in terms of their appearance. However, they play different positions on opposite sides of an at-bat.
Who is Mason McGwire?
Born Jan. 5, 2004 in Irvine, Calfornia, Mason is the son of Mark and looks just like him. His father, of course, is one of the greatest hitters in Major League Baseball history. The former Athletics and Cardinals slugger won two World Series, three Silver Slugger Awards, AL Rookie of the Year and a Gold Glove, and led the league in home runs in five different seasons. His resume speaks for itself.
Mason McGwire did not follow exactly in his dad’s footsteps. He and his big brother, Max, both play baseball— but he is a pitcher and not a hitter.
The 6-foot-4, 190-pound righty was drafted in the eighth round of the 2022 MLB Draft with the No. 233 overall pick by the Chicago Cubs. His fastball was clocked at 92mph in high school.
But he was best known for his splitter.
Mason, unlike his older brother, ultimately decided to forgo his commitment to the University of Oklahoma to go pro. The Cubs are obviously excited about his potential as a long-term developmental prospect, especially if he is able to fill out physically and add more velocity to his heater.
Mark McGwire’s son is on fire in 2026.
The first two years of Mason McGwire’s professional career were pretty underwhelming but they showed signs of what he could become. He recorded a 9.42 ERA with six losses and only one win in 35.1 innings pitched over 10 starts as a 19-year-old rookie in 2023.
He finished with a 5.71 ERA with four losses in 41 innings pitched of eight starts as a 20-year-old sophomore on the Class A level of competition in 2024. Numbers aside, the potential was clear.
McGwire threw strikes and a lot of them. He would just get tagged when he left one hanging.
An injury kept him off of the field for all of 2025. McGwire is back to full health in 2026.
The 22-year-old has pitched 10 innings in four appearances with one start for the Myrtle Beach Pelicans of the Carolina League on the Class A level. His 0.90 ERA speaks for itself but his strikeout total is even more impressive.
McGwire struck out 15 of 39 batters faced so far this season with only four hits and five walks allowed. He most recently fanned five batters in four near-perfect frames against Kannapolis.
This McGwire is responsible for zero runs 👀@Cubs prospect Mason McGwire (son of Mark) lowers his ERA to 0.90 with 5 K's in four near-perfect frames for @Pelicanbaseball. pic.twitter.com/zbdcea3S2F
— Minor League Baseball (@MiLB) April 20, 2026
Mason McGwire has pitched nearly one-fourth of his career season-high innings already this season. The Chicago Cubs are not in any rush to climb him up the ladder but he is making too much noise not to consider a promotion. If the son of Mark McGwire continues to deal like he is, Double-A will be the next test. That could come sooner than most people expected!