The LA Galaxy are on a tear in MLS, losing just twice in its last 20 games and rising to second place in the Western Conference. But LA coach Bruce Arena is about to receive “a major fine,” MLS commissioner Don Garber told SI.com, for Arena’s provocative comments about the league in a recent Washington Post piece.

Arena criticized the single-entity league after the Galaxy’s efforts to sign SachaKljestan fell through in early August before the league’s incoming-player transfer deadline. LA had traded KofiOpare to D.C. United to move up in the MLS allocation order, and Arena said the Galaxy had the budget room and space to sign Kljestan. “I won’t go into detail and just say forces within the league worked real hard to make sure that didn’t happen,” Arena told the Post’s Steven Goff.

Arena added: “They are children, and there have to be adults in the process, and we didn’t have enough of them. I think we are back into the old days in the league where the rules are somewhat arbitrary.”

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Garber was recovering at home from prostate cancer surgery during the month of August (he said he’s now cancer-free), but during his first major interview since returning to work he grew animated when asked to respond to Arena’s comments. “Bruce has the opportunity to be our Tom Landry, our Pat Riley, and he continually puts himself in a position where he acts unprofessionally and he emotionally misstates the facts,” Garber told SI.com last Thursday. “And I think that’s a shame.”

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​“In the case of SachaKljestan, he wanted to come to MLS and play for six months and live in Los Angeles so that he could then go back to Anderlecht [his current club],” Garber continued. “We are not going to sign a six-month contract with any player, whether Bruce Arena wants us to or not. His comments were false and inappropriate and will be dealt with … It will be a major fine.”

Kljestan’s agent, Richard Motzkin, said several clubs had been interested in Kljestan, both in Europe and in MLS, adding: “Had the right opportunity for Sacha presented itself within MLS, then he would have been prepared to commit long-term to the league. However, that was not the case at the time.”

In his Washington Post interview, Arena, who was fined $2,000 last summer for criticizing officials, also indicated his dissatisfaction with the financial restrictions of the single-entity league, arguing that MLS is now established enough that it’s here to stay. But Garber says single-entity isn’t going anywhere.

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“Single entity, as I remind everybody who asks me, is a mechanism that provides our owners the ability to make decisions collectively on everything related to the game,” Garber said. “That structure will remain the same. There are elements that we do decide to do together that might change over time—and have changed over time, particularly in our current collective bargaining agreement.”

“But the idea that owners will sit around a table and decide how they will collectively chart the turbulent waters of professional sports is something that I believe will always exist,” Garber added. “Because if it didn’t, Major League Soccer would not be here today, and I don’t believe it would be able to do what it needs to do in this incredibly competitive environment to succeed.”