Seattle general manager Jack Zduriencik said on Friday that the actions of Montero and cross-checker Butch Baccala were "unacceptable" and "embarrassing" for the club. Montero was being brought back to Seattle while Baccala was told to return to his home in the Bay Area and await internal discussions regarding discipline.
Zduriencik made it clear Montero would not play again this year prior to Friday's game against the Nationals.
"He is not going to participate in anymore baseball the rest of the year with us," Zduriencik said. "That's just the way it is. It's not going to happen."
The altercation occurred Thursday during Montero's rehabilitation of an oblique injury with the team's Class A Everett AquaSox affiliate.
According to MiLB.com, Montero was coaching first base when Baccala yelled at him to hustle off the field at the conclusion of the inning. A game official said the scout then ordered an ice cream sandwich and had it sent to Montero in the dugout.
Montero -- who made news for reporting to spring training 40 pounds overweight this season -- did not appreciate the gesture. He approached the stands with a baseball bat, screaming profanities, and threw the ice cream sandwich at Baccala. Montero had to be restrained by the team's pitching coach, according to the game's official scorer.
Montero, who joined the AquaSox this week and was scheduled to be added to the roster Friday, remained in the team's dugout until the game was over.
"First off, it is clear that both Jesus Montero and Butch Baccala engaged in behavior that is far below what we expect from members of our organization, including bad judgment at nearly every stage of this incident," Zduriencik said.
"I want to apologize on behalf of the Mariners franchise to the Boise Hawks (who played the AquaSox on Thursday) and their fans. We recognize that fans, including children, were impacted by this incident, and the language that was used. We recognize the severity of this incident, and want to assure the Hawks and their fans that it will be dealt with appropriately."
The Mariners sent Montero to the minors in late May. He has had only 17 at-bats with Seattle this season.
"We will issue further information when it is appropriate as we deal with this unfortunate incident," Zduriencik said.
Baccala told The Seattle Times that details of the incident are not fully accurate and that he wouldn't be able to discuss them until he spoke with Zduriencik.
"It's not what is being portrayed,'' Baccala told the newspaper Friday.
He also said he was not trying to provoke Montero.
"Of course I wasn't,'' Baccala said. "Why would I? I work for the Mariners. I've worked my [tail] off for the Mariners. Why would I do anything to hurt anybody? That wasn't even close to the intention.''
Montero was suspended 50 games in 2013 as part of the Biogenesis probe, and the 24-year-old reported for spring training in February overweight and out of shape.
"There's always two sides to a story," Zduriencik said. "But it really doesn't matter. This incident is of the magnitude that either party should have been more under control. Either party should have been more professional. You just don't get to this point and say neither is to blame or who is to cast the blame. It doesn't really matter. There is always two sides to every story. In the end, I would view this as saying both parties are wrong."
Montero's future in baseball may now be the biggest question. This is the latest in a string of issues that has seen Montero tumble from being viewed as a top minor league prospect. He was the centerpiece of a trade between the Mariners and Yankees that sent pitcher Michael Pineda to New York. Montero hit .260 with 15 homers in his first full major league season with the Mariners in 2012, but his career has had a downward tilt since.
Zduriencik said the team will focus on addressing all of Montero's issues beyond just baseball.
"We are going to separate the baseball part of Jesus Montero from the human element part of Jesus Montero. Our intent is to address Jesus' issues. There's a history here of things that have happened. We are very, very disappointed in him," Zduriencik said. "I think more than anything else, from a human standpoint, we have to look at Jesus Montero as a person, as a father and as a husband and how can we help Jesus Montero and his family get through this. That's our intent. That's our first and foremost intent. We are in the process as we speak."
Information from The Associated Press was used in this report.