Officially, Welke will be vice president of scouting operations.
In fact, he was on the job Monday, driving to Frisco, Texas, to see the Padres' Double-A affiliate, the San Antonio Missions. He'll be in San Diego on Sunday.
He's expected to be involved in amateur and professional scouting, foreign scouting, seeing the Padres' Minor League affiliates and might be around the Major League team more moving forward, Welke said.
Welke was a senior special assistant with the Rangers. From a distance, it appeared their reunion in San Diego seemed unlikely considering there were restrictions -- a reported two-year embargo -- on hires by Preller from the Rangers.
But Welke's circumstances, apparently, were different because of their relationship.
"I talked with [Rangers general manager Jon Daniels] and he said, 'I know your relationship with A.J goes way back,'" Welke said.
Preller is looking forward to working with his mentor once again and feels that Welke will thrive in his new environment.
"The biggest thing is the years of experience he has," Preller said late Tuesday. "He enjoys being part of a process and building. And he enjoys working with scouts. That's his passion."
The Rangers are going to miss Welke, Daniels said in a statement.
"He has had a profound impact on our organization, both on and off the field. His eye for talent, genuine care for people, and unique bonds with all of us will be missed," Daniels said. "He is both a mentor and a friend, and we will miss his quirks on a day to day basis. The Padres are lucky to have him. Take care of him for us."
Welke, who has previously scouted for the Blue Jays, Dodgers, Reds, Royals and Orioles, first met Preller when both were employed by the Dodgers -- Welke the scout and Preller working in baseball operations in 2003.
"He's like a son to me," Welke said recently.
The two would meet at the Pantry Café in downtown Los Angeles, a 24-hour diner, talking baseball long into the night, or at Jerry's Famous Deli in Marina Del Ray, Calif., near Venice Beach.
At Jerry's, Welke said, tables would be filled with would-be screenwriters, hoping to become the "next big thing." But the "next big thing" was sitting across from Welke the entire time, even if Preller had no idea. Welke saw it early on, though.
"He loved baseball and loved to talk baseball, was a baseball rat," Welke said. "We'd sit there until what seemed like 4 or 5 in the morning. He hungered for knowledge. We'd talk about different facets of the game. For a young guy getting his start, he had a great feel for what was going on."
By this time, Preller had already started thinking about the scouting and player evaluation. But late-night talks with Welke only served to increase his passion for that end of the game exponentially.
"Don is pretty close to the vest in a lot of cases. But for whatever reason, he opened that door up to me. Looking back, I got a real baseball education in those times," Preller said recently.
Welke has intentions of planting his roots in San Diego and will move there in the not-so-distant future.
"I plan to spend the next 20 years [doing this job] and then, who knows what … maybe I'll watch TV or I will be a part-time scout or something," Welke said, laughing.
"But I like the city and the challenge. We want to see a World Series in San Diego."