Madrid wrapped up their unbeaten Champions League Group A campaign with an 8-0 win over Malmo on Tuesday but Casillas was unable to help Porto into the last 16 as they lost to Chelsea at Stamford Bridge a day later.
Casillas made 725 appearances for Madrid over a 25-year association with the club before joining Porto in July and is hopeful of taking on his former employers in next year’s Super Cup.
“I hope it all goes well for Madrid,” he is quoted as saying by AS.
“They are through to the next round and I hope we can both win and meet each other in the Super Cup next year.”
Porto were undone by an Ivan Marcano own-goal and Willian’s second-half strike at Stamford Bridge, with Julen Lopetegui’s men slipping to third behind Dynamo Kiev.
Amid criticism for their failure to reach the knockout stages, Casillas added: “That’s football, when you have a bad result it’s difficult. We needed to win but we have to think about the future and the new challenge we have.
“We made a couple of mistakes and we’re out of the elite competition, but the Europa League will be another challenge.
“Of course we wanted to go through in the Champions League, but you have to know how to accept defeats. The Europa League is a new competition for me and I’m looking forward to it.
“We’ll try and do the best we can.”