Spurs were surprisingly beaten 1-0 by the Belgian side in the initial bout on Thursday and will be looking to overturn that deficit at Wembley this Thursday.
The North Londoners defeated Fulham 3-0 in the FA Cup fifth round round on Sunday thanks to a Harry Kane hat-trick but Mauricio Pochettino says his players will have to swiftly put that behind them as they prepare for the visit of Gent.
"We have to focus on Thursday, forget this and try to be focused," he said.
"Thursday is a massive, massive game for us.
"We need to feel we must win and go to the next round, and now we're not allowed to speak about the FA Cup."