Dunn was not in the starting lineup and dropped in during the bottom of the second inning to talk to the 75-year-old announcer who returned to the booth on Friday night for the first time since undergoing heart surgery.
Both Uecker and Dunn wanted to downplay the appearance on Sunday.
"It was good. I've known that guy for a long time. To get to see him healthy and having fun and back doing what he love is great," Dunn said.
Dunn, known for his jovial nature, imposing stature and even bigger bat, didn't want to discuss whether his decision to slip out of the clubhouse and chat with the venerable announcer would be an issue.
"I could care less if I get in trouble for going up and seeing my guy after he had heart surgery," Dunn said. "I'll pay my fine."
Uecker, in his 40th season behind the mic, can be heard in the clubhouses and concourses of Miller Park. He had been talking about Dunn earlier in the game, and the slugger was on only briefly to talk about fishing with Uecker before returning to the clubhouse.
"He's one of my all-time favorite guys," said Uecker, who didn't know Dunn was coming and didn't want Dunn to get into trouble. "He scared me because he was kneeling down behind me. Said he wanted to see me in case I expired."
Still, it was hard to keep the appearance quiet. Dunn dropped in on the Brewers' flagship, WTMJ-AM, a 50,000-watt station that also distributes the game to 35 markets.
One guy was left out -- Nationals manager Jim Riggleman.
"I wish you hadn't told me that," he said. "I don't have any comment on that."
Dunn later entered the game as a pinch hitter in the top of the ninth and hit a sacrifice fly that tied the game. Washington lost 4-3 in the bottom of the inning on Ryan Braun's RBI single.