Now all three have adjacent lockers in the visiting clubhouse at Nationals Park.
The relief pitchers have been called up this week from Nashville to give life to a Brewers bullpen that has struggled through injury and extended use.
"We're real close," Jackson said. "We've got a tight-knit group of guys."
Dillard was the latest callup, arriving Friday to take the place of closer Eric Gagne, who was put on the 15-day disabled list with right rotator cuff tendinitis. Gagne was only supposed to miss a few days with the injury, but was moved to the DL to create room for another bullpen arm. Manager Ned Yost said the callups will also allow Gagne to take his rehab slowly.
"I don't think he needs 15 days either," Yost said. "I don't want to rush him. I want him to get healthy. I want him to get through this, because he's a competitor, and he'd battle through it even if he weren't 100 percent. So this takes some of that uncertainty out."
As for Jackson, DiFelice and Dillard, the manager described them as guys who are with Milwaukee to fill holes in the bullpen.
That's fine by Jackson, who is looking to take advantage of his time with the big league club, no matter how short it is.
"It's all about timing," he said. "It's about timing and taking advantage of it. I speak for all of us when I say that we're grateful for the opportunity."
DiFelice and Jackson were originally starting pitchers, and their time in that role gave them arm strength that the Brewers are looking for right now.
The team has struggled to find starters for the fourth and fifth spots in the rotation, with Dave Bush having subpar outings recently and Carlos Villanueva being demoted from the fifth spot after his last start.
On Saturday, the start will go to former reliever Seth McClung, who won't be ready to make a full outing, but Yost said that with the arms available, finding pitchers wouldn't be a problem.
"Villanueva is behind him, and it's his day to pitch, so we're covered," Yost said.
The three Nashville callups will also be available. Dillard pitched one inning on Friday, getting every batter he faced out in his Major League debut.
DiFelice made his first appearance last Sunday in Boston. At age 31, he became the third-oldest player in Brewers history to make his Major Leauge debut. He also threw Thursday in Pittsburgh, a one-inning outing that drew a positive review from Yost.
Jackson last pitched on Thursday as well. He was a starter earlier this season in Nashville, so he remains able to go long stretches when the Brewers have a need for that. He said he's just happy to be with the club.
"Whenever we get called on, whether it's situational or whatever, we'll be ready," Jackson said. "We're up here for a reason -- to attack the zone and throw strikes."
Michael Phillips is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.