Barca have this week been hit with a 14-month transfer ban by FIFA.
The news has cast doubt over Halilovic's future, after Barca agreed a deal with Dinamo Zagreb last month to bring in the Croatian teenager this summer.
"I called the Barcelona board and got an assurance that the sentence does not affect the transfer of Alen Halilovic," Mamic told Sportske Novosti.
"Everything is fine, there is no need for speculation. Alen will move to Barcelona after this season, that is for sure.
"The contract is signed and you can be sure that nothing unusual will happen."
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