Robben was on target inside 14 minutes in Bayern's Bundesliga opener last night, a 3-1 success over Borussia Monchengladbach.
The Dutch winger thinks that his side are still adjusting to Guardiola's methods, but praised their aggression in the final third against Gladbach.
He said: "The important thing is that we always want to play dominantly and we want to put pressure on going forwards and be aggressive. We did that partly well tonight.
"It's only normal that when a new coach comes, there are minor changes and these need time.
"We are not where we have to be yet. Some things can still improve. We will get better in the coming weeks."