Vitek was superb on the day, but was beaten late on by Noah Holm as RBK won 1-0.
"We are disappointed as I feel like we should always aim for a win, the manager said we don't play friendlies as it is in our DNA. We should demand more," Vitek told MUTV post-match.
"We are building up now as it is only our first week of pre-season, so we are still waiting for some more boys (to arrive back) from their internationals.
"But as I said, in the end, all that matters is winning."
He added: "It is really good that the young lads are getting the opportunity as when you step on the field you have to show yourself.
"It is a big opportunity in front of a lot of people that are watching you. You have to demand the best from yourself.
"It is an amazing feeling as the fans have been amazing. Lots of them at our hotel, even in the stadium the crowd was amazing: a full stadium of Red shirts."