One recent morning in Phoenix, Juan Soto, a star outfielder for the New York Yankees, was watching TV in the visiting clubhouse when an attendant approached him to ask a favor.
In the attendant’s hand were a ballpoint pen and an unblemished baseball, protectively placed in a plastic bag — the telltale ingredients of an autograph request.
The attendant wasn’t asking for himself, however. “It’s for Zac Gallen,” he told Mr. Soto, referring to the star pitcher for the Arizona Diamondbacks. Mr. Soto barely looked away from the screen as he accepted the ball and pen. By the end of the day, a Soto-signed baseball awaited Mr. Gallen in his locker.
The interaction was performed with nonchalance. Among players in Major League Baseball, requesting a fellow player’s autograph is nearly as common as being asked for one by a fan. The players, aware of how fleeting careers can be, collect memorabilia in the truest sense of the term — a way to remember the greats with whom they shared the field.
“It dawned upon me that I’m not going to play forever,” Mr. Gallen said, “and I’m not going to have the opportunity to get guys I’ve competed against.”
Players rarely decline to sign for their peers. “I really do think 99.9 percent of players view it as the highest compliment,” said Jameson Taillon, a pitcher for the Chicago Cubs. But the major leagues’ mutual admiration society has a few unspoken rules.
Every player is constantly hounded for autographs, by fans or marketing people seeking signed items for charities or giveaways, so players keep the volume of requests in mind when approaching their peers.
The first hurdle is considering yourself a peer at all. Veteran players don’t police autograph seeking as much as young players do, considering themselves too inconsequential to bother older players.
“As a rookie, it’s kind of intimidating,” said Archie Bradley, a free-agent pitcher who most recently played for the Miami Marlins. “You have this view of yourself like, ‘Am I good enough to ask for an autograph?’”
Some of the best players felt the same when they were rookies.
“I don’t think I was worthy of asking for anything yet,” said Nolan Arenado of the St. Louis Cardinals. “That’s how I saw it.”
Memorabilia-minded players eventually overcome that shyness — often because their careers are nearing an end or an all-time great is on his last lap. When Derek Jeter, the Yankees shortstop and captain, entered his final season in 2014, he let it be known that he would sign for any fellow big-leaguer who asked.
In 2022, the hot collectible among players was any item signed by Albert Pujols, who had announced he would retire at the end of the season.
That move is partly what spurred Mr. Gallen into collecting. Despite having established himself as an elite pitcher, the right-hander was nervous talking to Mr. Pujols before a game.
“He was trying to have a conversation with me and interact, and I was just trying to get out of his way,” Mr. Gallen recalled. “I didn’t want to take up any of his time.”
Mr. Pujols preferred to be approached in person: The longtime Giants shortstop Brandon Crawford, now with the Cardinals, made his request upon reaching first base during a game. But pregame hours are busy and such meetings can be difficult to arrange.
The next best option is to send a handwritten note. Mr. Bradley has written heartfelt messages to David Ortiz and C.C. Sabathia, among others, explaining their impact on his career. He also asks that signed items be personalized, signaling to autograph-weary players that whatever they sign won’t end up on eBay.
Little of this happens, though, without clubhouse attendants. They’re the ones who ferry requests and signed items from one clubhouse to another.
Shawn Moore, the attendant in Arizona who approached Mr. Soto on Mr. Gallen’s behalf, is the Diamondbacks’ designated signature seeker. Once a series, usually in the middle of a three-game set, he’ll enter the visiting clubhouse and pass along requests from the home team.
By the end of the series, Mr. Moore has fulfilled most requests. At last year’s All-Star Game in Seattle, Mr. Gallen said, Mr. Moore needed just a half-hour to land the pitcher a pair of cleats signed by the Hall of Famer Ken Griffey Jr.
That kind of effort is appreciated, with players offering attendants cash tips or some other thoughtful gesture. It can be small, maybe a coffee or a sandwich from the shop down the street, but it keeps baseball’s peer-to-peer autograph system humming. “Kindness begets kindness,” Mr. Moore said.
A similar system of reciprocity governs larger requests. Asking for a signed baseball is easy — players sign those frequently. But the game’s more motivated collectors aim higher.
In Mr. Gallen’s case, he is seeking more unique items as he tries to outfit a bar in his home, and Mr. Arenado wants to fill the walls of his private batting cage, and jerseys and gear take up more wall space than baseballs do. That usually means purchasing a replica at the team shop and sending it over for a player to sign.
Sometimes, they’re lucky enough to get the real thing. Though Mr. Gallen didn’t request it, Mr. Pujols sent him a signed Cardinals jersey straight out of his locker.
Implicit in such a request is a willingness to return the favor: a jersey for a jersey, a glove for a glove, cleats for cleats. With so many players wearing custom kicks, cleats are an especially popular target. Mr. Bradley bought shoe store racks to display the many he has, including cleats from the Yankees star Aaron Judge and the Philadelphia Phillies first baseman Bryce Harper — and a rare pair of Asics spikes from the two-way star Shohei Ohtani, who has since switched shoe companies.
Mr. Bradley always offers up some of his own gear, although he said as a reliever, “Most guys don’t ask for anything in return from Archie.” He also makes clear that he wants to display them, not wear them. Most players don’t need the clarification, though Mr. Arenado once gave a pair of spikes to Adam Jones, an outfielder for an opposing team, only for Mr. Jones to wear them in the game that night.
“He hit a double and was like, ‘These things got hits!’” Mr. Arenado said. “I was like: ‘You can’t do that to me! My teammates are watching you wear my cleats!’”
That hasn’t made Mr. Arenado any less likely to give away his gear. He’s both flattered when asked and grateful when someone gives something to him. That’s true for most players, although some are still tough to land. Zack Greinke, a star pitcher with 20 seasons in the majors, has been known to turn down players and throw up playful obstacles.
When they were teammates in Arizona, Mr. Greinke once offered Mr. Bradley the collectible of all collectibles: one of Mr. Greinke’s cars, with his signature on the dashboard and a glove signed by Mr. Greinke thrown in as a bonus.
All of that could be had for the low price of $1,000 less than the vehicle’s Kelley Blue Book value. The only catch was that Mr. Bradley would also have to provide an autograph from another player whom Mr. Greinke knew he absolutely despised.
Mr. Bradley could only laugh at the sheer deviousness.
Was Mr. Bradley willing to go that far? Does he have a Greinke signature in his collection?
“I don’t,” he said with a chuckle. “Yet.”