The Celtic captain is currently serving a three-game ban for a kick at Barcelona playmaker Neymar when the teams met earlier this month.
Brown missed the Ajax game last week and is due to sit out next Wednesday's meeting against the Dutch champions as well as the following game against AC Milan.
"I've said all along that it has been harsh," said Lennon. "It would be a big boost for us if the suspension was reduced but all we can do is wait and see.
"He will get the chance to plead his case and we'll see where that leaves us."