PHOENIX (AP) \u2014 Nolan Arenado was slugging his way through the month of May when the Arizona Diamondbacks third baseman woke up one morning with an ailment that’s familiar to those who felt invincible in their 20s but have advanced to their mid-to-late 30s.<\/p>\n
His back hurt.<\/p>\n
Not bad. Not enough to keep him out of the lineup. But it was one of those inexplicable moments that comes with being an aging Major League Baseball<\/a> player \u2014 threatening to derail a hot streak for an eight-time All-Star who just turned 35.<\/p>\n \u201cThere’s more aches and pains,\u201d Arenado said. \u201cThere’s just a little more work in the gym, getting prepared for the game, than there used to be. That’s a learning curve. <\/p>\n “I’ve always been in the gym, always did that stuff, but there’s definitely more maintenance.\u201d<\/p>\n Arenado got past the minor back issue and is continuing a bounce-back season in the desert, batting .256 with eight homers and 30 RBIs through Monday’s games. He’s among a group of the 35-and-older crowd getting solid results at the plate, joining Los Angeles Dodgers veterans Freddie Freeman and Max Muncy, along with Houston’s Christian Walker.<\/p>\n But it’s a small club that’s become smaller over the past decade.<\/p>\n MLB hitters who are 35 or older have combined to provide just 5.6 WAR<\/a> (Wins Above Replacement, per FanGraphs) through roughly the first 1\/3 of the season, continuing a trend that’s accelerated over the past decade. <\/p>\n In the early 2000s, older stars were the norm in the big leagues. It peaked in 2003 when older hitters combined for 71.3 WAR, with a group highlighted by Barry Bonds, Frank Thomas, Kenny Lofton, Luis Gonzalez and Jeff Bagwell.<\/p>\n So what’s changed?<\/p>\n Let’s look at some of the reasons why MLB is skewing younger this days:<\/p>\n Analytics like younger players<\/p>\n Baseball’s analytical era can be traced back to the work of Bill James in the 1970s and 1980s, but terms like WAR, wOBA, BABIP, and OPS+ didn’t start to become widespread in the big leagues until at least the late 2000s.<\/p>\n Suddenly, the eye test wasn’t enough for MLB general managers. Cold, hard numbers were in.<\/p>\n And \u2014 overwhelmingly \u2014 those numbers showed that the best years for a big league hitter usually come from their mid-20s to early 30s.<\/p>\n That’s directly correlated to MLB teams locking up young players to long-term contracts. Arizona’s Corbin Carroll<\/a>, Detroit’s Kevin McGonigle<\/a>, Pittsburgh’s Konnor Griffin<\/a>, Kansas City’s Bobby Witt Jr.<\/a> and Seattle’s Julio Rodriguez<\/a> are among dozens of promising players who were signed to lucrative deals well before they reach free agency.<\/p>\n Spending on veterans is no longer in vogue. Walker \u2014 a three-time Gold Glove first baseman who has hit nearly 200 career homers \u2014 signed with the Astros for a relatively modest $60 million, three-year deal after the 2024 season when he was 33 years old.<\/p>\n \u201cI think it has a lot to do with the ability to measure guys\u2019 value on the field,\u201d Walker said. \u201cFor a long time, WAR didn\u2019t exist, wRC+<\/a> wasn\u2019t a stat, right? So, you went off of the optics or this guy\u2019s a good clubhouse guy or he\u2019s got experience, he\u2019s been to a World Series.\u201d<\/p>\n Velocity has exploded during their careers<\/p>\n Today’s young stars have come of age in a game where velocity is king, but it wasn’t that way when Freeman and others broke through. The average MLB fastball<\/a> in 2026 is north of 94 mph, with 18 qualified pitchers averaging at least 96. When Freeman debuted 17 years ago, the league-wide average was under 92 and no qualified pitchers averaged at least 96.<\/p>\n