The Republic of Ireland international believes that his team made a strong performance against United on Easter and were unlucky to end the game with a defeat.
"We definitely deserved to get something out of the game, and who knows, if we had scored first we might have won it," Sky Sports quoted Keane as saying on Wednesday.
"Sometimes you need a bit of luck, on Monday we had something like four or five chances in the space of ten minutes and it wasn’t to be, but we did play well," he added.
Tottenham play the Arsenal game in fourth position and the Highbury encounter will be decisive to determine who will be in next season's UEFA Champions League, as the Gunners hold fifth place, five points behind the Spurs.
However, Keane, who is Tottenham's top scorer in the premiership with 15 goals, is convinced that the Manchester United game should be helpful to him and to the Tottenham players as they need to give a similar strong game against Arsenal.
"It certainly was a strong performance (against Manchester Utd.) and we have to take a little bit of heart from it into Arsenal game," Keane said.