Sitting on the bench inside the Indians' dugout, Acta spoke softly and appeared upset while discussing the decision to part ways with Nunnally. The manager delivered the news to Nunnally, hired as Cleveland's hitting coach when Acta was brought on as manager last season, before Saturday's 5-1 win over the Pirates.
Fields, who has served as the Indians' Minor League hitting instructor since 2007 and previously served a hitting coach for the Tigers, will join the Major League staff on Monday in Cleveland. He was with Double-A Akron when he was offered the new job and was spending Sunday preparing for the move.
"We're hopeful that Bruce can be a resource," Indians general manager Chris Antonetti said. "But there's no magic answer in baseball."
Letting Nunnally go was not an easy call for Acta.
"It was very tough," Acta said. "It was one of my toughest days at work. I mean, [on Saturday] we won the game, and I didn't feel like celebrating. It was a hard decision to make."
Acta pointed to the club's offensive struggles in 2010, but it was the team's dramatic drop-off at the plate over the last month that forced the change.
Over the first 45 games this season, Cleveland hit .265 as a team with a .759 OPS. Over that span, the Indians went 30-15 and averaged 5.1 runs on nine hits with 6.9 strikeouts and 3.4 walks per game. Entering Sunday, the Tribe had gone 8-16 in the 24 games since that strong stretch.
During the recent skid, the Indians have hit .225 collectively with a .628 OPS. Along the way, the club has posted three runs on 7.4 hits with 7.9 strikeouts and 2.7 walks per game. Over the past 16 games, Cleveland had hit just .156 (17-for-109) with runners in scoring position.
As the slump persisted, the thought of making a personnel change increased.
"We make collective decisions," Antonetti said. "But obviously, this is Manny's coaching staff. He and I talked about it, and we came to a consensus that this was the right move for us. We don't make reactive decisions. We try to work through things and talk through all aspects of it before we reach a decision.
"The more extended our struggles were, offensively, certainly the more pronounced it became and the more conviction we had that we potentially could benefit by a different voice."
Given his history as a hitting coach in the Majors -- he held that role for Detroit from 2003-05 -- Fields was a logical choice. Beyond that, Field has a history with many of Cleveland's hitters from their days developing in the farm system. That fact was important for Acta.
"He just brings a ton of experience," Acta said. "The familiarity that he has with our players was a must."
That said, Cleveland's hitters were not necessarily thrilled with the decision.
When asked if he had a few minutes to talk about Nunnally, Indians outfielder Michael Brantley declined comment.
"Not right now," Brantley said. "Maybe later."
Indians right fielder Shin-Soo Choo was a little more candid, indicating that multiple players on the team were upset about Nunnally's dismissal. Choo said that he found the timing strange, considering that the Tribe, despite its recent struggles, entered Sunday in first place in the American League Central.
"We're in first place," Choo said. "It's sad. You wanted him to enjoy that with us, too. We're a family here. You don't want to lose somebody that's a part of what's been going on here. Hitting coaches and pitching coaches are so important.
"During the season, a new hitting coach comes in, it's tough. Everybody has different styles, but you don't want to think about new coaches coming in."
Choo hoped the players did not let the news affect them on the field.
"You don't want to feel like that," Choo said. "You don't want negative things, negative thoughts. For the last five or six weeks, we've been a little bit down. You try to start a winning streak. You don't want to think about bad things."
Acta and Antonetti both understand that the move was probably not a popular one.
"He's a very likeable guy," Acta said of Nunnally. "I love him, too, myself. But it's part of the business. I understand if some of them are a little upset, but we have to do what's best for our team.
"We think that, with so many games left during the season, Bruce can make an impact over here."
Antonetti echoed that sentiment.
"Any time you make a decision like this," Antonetti said, "especially with someone who you care so much about, it's always difficult. It's difficult on a personal level for all of us, but I'm confident in our players' professionalism, that they'll turn the page and embrace Bruce.
"This is not to say that it's any one person's fault. It's a collective challenge, and Nunns did everything he could to work with our guys to put them in a position to be successful. Unfortunately, as a team, we've struggled for a while, offensively."
Fields is in his sixth season in the Indians organization. He also served as hitting coach for Triple-A Buffalo in 2006. He played professionally from 1978-91, spending time with the Tigers and Mariners in the late '80s.
Fields' stay as the hitting coach is on an interim basis for the time being. The plan is for him to fill that role until the end of the season, when Acta and Antonetti will reevaluate the coaching staff for next year.
Antonetti, however, was quick to express "full confidence" in Fields.
The Indians' first-year GM also said he still has plenty of faith in the team's hitters.
"We understand that there are going to be peaks and valleys," Antonetti said. "We still believe fundamentally in the talent of the group of guys that are here. We think they have the ability to be collectively better than they've been in the last couple of weeks."