Jed Stephen “Kos” Kosmoski never batted for Concordia University, St. Paul’s baseball team and never shot a puck for Hamline University’s men’s hockey team.

Yet Kos, through his infectious enthusiasm for his teams and their players and his willingness to do tasks great and small, surely became a most valuable player over the years in St. Paul. It was his personality, his joy, his selflessness that makes the void he’s left behind all the more painful, said longtime Concordia baseball coach and athletic director Mark McKenzie.

“Somebody said, ‘Just think of what Concordia and Hamline did for that young person,’ ” McKenzie said of the man with special needs who started working part-time at Concordia in 2009. “But, really, think of what he did for them.”

Kosmoski, 44, died unexpectedly Aug. 5 in Seattle, stricken by pancreatitis while visiting his sister. A memorial service held Aug. 12 at Concordia’s Gangelhoff Center was attended by more than 600 people — many of whom shared stories and recollections about a man who mixed in hugs, jokes and fist-bumps with his official duties on the baseball diamond and the ice.

“He was an all-arounder for us,” Hamline men’s hockey coach Cory Laylin said. “He organized pucks and sticks, helped organize meals on the road. He was a conduit for the opposing coach. He was just such a selfless individual. He cared about everyone else.”

Sue Kosmoski said “we were amazed” by the crowd that attended her son’s memorial. But maybe they shouldn’t have been. After all, Kos was the kind of guy who could make a friend at the luggage carousel of an airport, as he did recently in Seattle. His sister noticed him talking to a man while they waited for their bags, Sue Kosmoski said.

“She said to the man, ‘Do you know each other?’ He said, ‘No, [Kos] just told me I had on a great tie. It made my day.’ ”

Making people’s day began for Kosmoski as a student manager at Wayzata High School, his mother recalled. He worked for as many of the school’s teams as he could fit into his schedule. “He loved sports,” she said.

That’s about the time McKenzie remembers meeting him, when McKenzie was the baseball coach for Minnetonka High School and saw Kosmoski racing around, shagging balls. They would reconnect after McKenzie moved to the Golden Bears in 2000. Kosmoski, who by then lived only four blocks from campus, was working at the school.

Tom Rubbelke, the previous athletic director, gave Kosmoski a job taking care of the school’s smaller weight room. It morphed into much more than that.

“He did so much for us,” McKenzie said. “He knew everyone’s name, what events they had in their lives, details about their families, if they were going fishing.”

McKenzie got a phone call from Kosmoski on July 23.

“He called from the hospital,” the coach said. “He said, ‘I might be late [for an upcoming practice].’ ”

The coach said it sounded as if he was in a lot of pain. “I told him, we don’t care if you’re late. Just get better and we love you,” McKenzie said.

Laylin, who said he knew that Kosmoski was in Seattle but didn’t know he was sick, was coaching a team in the Czech Republic when Kosmoski died.

“Guys on the team started texting me, asking, ‘Is it true?’ ” said Laylin, who spoke at Kosmoski’s memorial with Mc­Kenzie and several players. “We are going to really miss him. He had so much life in him.”

Kosmoski is survived by his parents, Jim and Sue Kosmoski of Minnetonka, and a sister, Molly Kosmoski-Wilson of Poulsbo, Wash.