When he left the club, Ljungberg suggested Arsenal were in decline, but has since back-tracked.
"You don't bear grudges with Freddie because I know he's an honest guy, I will always love Freddie, no matter what he says because I have gone through difficult and many things with him," said Wenger.
"I know he's not a guy whose mischievous. Today he changed his mind, fair play to him."
Wenger added: "He got a three-year contract at the age of 30 and he had an opportunity to play.
"Freddie was always a very important player here, he was a fantastic player for Arsenal and he decided in the end to go for a new challenge. I respect that."
The Gunners boss, however, maintained letting Ljungberg go was necessary to the development of the squad.
Wenger said: "I have to make decisions and I cannot get young players in the team while keeping the old ones in as well.
"When you see the competition become hard, you have to make room for the younger players.
"At the beginning of the season, I said there was a hunger and togetherness in the team and there is great quality there.
"How far they can go I don't know, but I was confident we could start well because our schedule was potentially winnable.
"We have done well and that has strengthened our belief, but tomorrow is a big test.
"We can show that we are stronger than last year."