Five days after Bayern announced Van Gaal would leave at the end of the season, they demolished Hamburg SV 6-0 on Saturday to restore confidence after three successive defeats.
Van Gaal, whose contract was due to expire in 2012, has paid the price for a poor campaign after the club's domestic double last season, but the Dutchman can still go out on a high in the Champions League.
Bayern, who lost to Inter in last year's European Cup final, host the Italians in the second leg of their last-16 tie after winning 1-0 at the San Siro last month.
"Everyone saw (against Hamburg) how Bayern can really play," Van Gaal said.
"The goals liberated us and this was just the perfect preparation going into the game against Inter."
"We said changes have to start now, to support each other more," said Dutch winger Arjen Robben, who scored a hat-trick against Hamburg to make it eight goals in eight league games since he returned from a six-month injury lay-off.
"I saw our players become more confident and that is how we must continue."
Former Bayern defender Lucio is a major doubt for Inter. The Brazilian was replaced by Ivan Cordoba with 25 minutes to go of Friday's 1-1 Serie A draw with Brescia after pulling a muscle in his right leg.
Lucio's presence is considered crucial with fellow centre-back Walter Samuel already out for the season.
With Giampaolo Pazzini cup-tied, Goran Pandev, whose performances have been more impressive of late, is likely to partner the in-form Samuel Eto'o up front.
Inter Milan: 1-Julio Cesar; 13-Maicon, 15-Andrea Ranocchia, 6-Lucio, 26- Cristian Chivu; 4-Javier Zanetti, 19-Esteban Cambiasso, 5-Dejan Stankovic, 10 Wesley Sneijder; 9-Samuel Eto'o, 27-Goran Pandev.
