The Slovokian asked to be released from his contract with immediate effect in the wake of Sunday's 5-1 victory over Sheffield Steeldogs.
He is now set to continue his career in Kazakstan and will be a big loss to Bees after playing a starring role in the first few months of the season.
He leads the scoring charts for defenceman in the English Premier Ice Hockey League with 12 goals in 23 matches - including one against Steeldogs in his final game - and was named Bees' player of the month for November.
"He was a very important player for us," Cox told the News. "He scored a lot of goals and also added a lot to the powerplay unit.
"But he wants to go and pursue his career elsewhere so good luck to him. There is nothing we can do about it."
The departure comes at a difficult time for Bees as most players will already be tied down with teams for the season.
But Cox, along with assistant Lukas Smital and experienced player Martin Masa, have already begun their search for a replacement.
"Between myself, Smits and Marty we have a few contacts so hopefully in the next few weeks we should be able to get something sorted out," said Cox.
"It's one of those situations, we can't do anything about it and we have to see who is available. "It's tricky because it's during the season but hopefully other players will come to the fore in the next few weeks and we also have the Hornets who can step up if needed."
Bees will boosted by the return of Andy Munroe for their games with Manchester Phoenix and Sheffield Steeldogs this weekend after he missed last Sunday's clash with Steeldogs.
While Bees hold the edge over Sheffield this season after beating them twice in three outings, their only meeting with Phoenix saw them suffer their heaviest loss of the campaign.
So Cox knows his side will have to be at their best for the clash at The Hive on Saturday (6pm f/o) especially.
"We have to make sure we play better than we did last time at their place, and we have to make sure that we come out and perform to our best," he said.
"It all comes down to us and how we perform, we have to perform to our potential and then we will get results."