The Italians beat Spurs LE 1-0 at San Siro last month but suffered a Serie A setback as their four-game winning streak in all competitions ended with Saturday's 2-1 loss at Fiorentina.
"This is a different story compared to Florence, but also compared to the first leg," Pioli told a news conference on Tuesday.
"I expect a different attitude from them... Tottenham will probably try to attack more than at San Siro."
The visitors have been boosted as forward Brahim Diaz (23) and striker Olivier Giroud (36) will both be available for the clash after they rejoined the team in training on Tuesday.
"They're both doing well, all 24 players can play from the start, then I'll make the choices," Pioli said.
Both players were a doubt for the London trip after Diaz missed the game at Fiorentina with a knee problem while Giroud did not train on Monday due to flu, Italian media reported.
Tottenham's Italian boss Antonio Conte (53) will be back on the touchline on Wednesday after gallbladder surgery kept him out of action for a month, which will help Spurs according to Pioli.
"The presence of the coach is important, I speak from personal experience. Conte is an added value and beyond him we will find a very motivated opponent," he said.
"Tomorrow is the match of personalities. Our opponents are formidable from an offensive point of view.
"They will play with great intensity and we must be prepared to control the game more. We have a very small advantage but we cannot think of managing it," he added.