Miami, Florida - Major League Soccer commissioner Don Garber has hit out at referee union members after talks broke down leaving the league to start the new season without their top referees.

Garber, speaking to reporters prior to the opening game of the season between Inter Miami and Real Salt Lake, warned MLS was "very prepared" to deal with the lockout of the officials.

The Professional Soccer Referees Association (PSRA) said on Saturday that 95.8% of their voting members had voted to reject the tentative deal they had reached with MLS' Professional Referees Organization (PRO).

"I can't remember in my near 40 years of sports of having a bargaining unit reach agreement and not have their members support it," Garber told reporters, saying that over 20 bargaining sessions had been held before the deal was reached between negotiators.

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"Very disappointing process. In my opinion, it was one that either was intentional or there's a disconnect between the members and their elected negotiators," he said.

"It's not the way MLS was looking to start a season, but you can't really negotiate with an entity that, in my opinion, hasn't really negotiated with PRO fairly. So we'll see how all that plays out in the weeks to come," he added.

The referees' previous five-year labor deal expired in January, with workers demanding fair wages and benefits during negotiations.

PSRA said the rejected deal fell "short of expectations, along with a lack of quality of life improvements," but Garber said it was not clear to him what the main issues were that needed resolving.

"At this point, we don't even know what it is that they're looking for because we agreed (a deal) with their elected representation," he said.

"Not knowing what it is and how far PRO is apart from the PSRA, that is just not something that I can say is normal in a bargaining unit right now."

The PSRA responded quickly to Garber's comments on social media.

"If the Commissioner doesn't know what we want, he should simply ask his own Negotiating Committee. We have made it clear: 'PRO negotiators failed to heed PSRA's warnings at the table that the TA (agreement) would fall short of membership expectations and face an uphill ratification process,'" the union posted.

PSRA members earlier staged protests on Wednesday outside MLS's offices in midtown Manhattan and in Arlington, Texas.

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"My hope would be that they would have come and told us what it was that the officials were looking for that their elected representatives were not able to deliver for them rather than spending their time on protesting outside our offices," said Garber.

"So I'm sitting here today not quite sure what the next step is. I don't know how you get to a point where there's work stoppage and not know what it is that you're disagreeing about."

"That's frustrating. I imagine it's frustrating for fans. It's certainly frustrating for us. We'll see how it plays out. I will tell you that we are very prepared."

"We're more than willing to manage this in a way that's in the best interest of our players, our teams, the best interest of our fans," he said.