McClung worked a scoreless inning Saturday, then he got the good news from Brewers principal owner Mark Attanasio.
"Mark came over and shook my hand and told me congratulations on making the team," McClung said. "I don't want to say it's nerve-wracking waiting -- you just have to stay back and do your job.
"This year is much more exciting than any point in my career, because we have such a future to look forward to this season."
McClung is entering his first full season in the Brewers organization after parts of nine years with Tampa Bay. He went 2-0 with a 4.15 ERA in eight Spring Training games and is on a big league Opening Day roster for the fourth time in his career.
Even with three years, 111 days of Major League service, McClung is the young buck of the Brewers' veteran-stocked bullpen. That means he must lug the bag of gum and candy to the bullpen every day, a job that usually falls to a rookie.
"If that is, in fact, one of my duties," McClung said, "it will be a darn good candy bag."
Dillon, meanwhile, is going on his 11th professional season, but he is breaking camp in the big leagues for the first time. He earned his spot by batting .328 in Spring Training games, and he will serve as a backup at first, second and third base and left field.
The Brewers, like most clubs, wait until the final moment to set their roster, guarding against unforeseen injuries, trades or waiver-wire pickups. Was the team pursuing any last-minute moves?
"Not at this time," general manager Doug Melvin said. "I think we're pretty set with the club that we have. We put it together in the offseason, [and] watched them perform for 30-some games in Spring Training.
"I'm not saying there won't be areas during the course of the year, but right now we need to let the players go out and play, give them the benefit of the doubt and let them show us what they can do. There's nothing that I feel needs to be addressed at this point."