The Cameroon international was recently called up to his nation's squad for the upcoming Africa Cup of Nations, with on-loan midfielder Sofyan Amrabat also being selected for Morocco.
In his press conference on Thursday, Erik confirmed that he expects Onana to be available for the 20:15 GMT kick-off at the DW Stadium on Monday night.
"So, we're talking with [the] Cameroon Federation," said the boss. "It was an issue during the talks with Andre when he came in here, and it's constructive, so we will see.
"I don't know yet [if he will be with us for the Tottenham game on 14 January] but he will be there for the game against Wigan.