Ramos was replaced by Harry Redknapp on Saturday.
The two sides will clash in the North London derby on Wednesday.
Wenger said: “I don’t think he’d have been sacked if he had only arrived at Tottenham in July.
“But the fact is he arrived in the middle of last season and people were less patient with their league position.
“What sometimes happens in this league is when a team doesn’t go for Europe and wins the Carling Cup, they suddenly switch off.
“Without anyone noticing, slowly you lose results. And then, if you don’t start the next season well, which is what happened to Ramos, his environment slowly lost confidence in him.
“I am very surprised it didn’t work for Ramos and I feel sorry for him because I rate him as a coach and as a man.
“It takes time to get your ideas through. I understand Tottenham have to make decisions but you would want anyone to be given more than eight or nine games.
“Now they have gone a completely different way and done away with the director of football because they were suddenly convinced it doesn’t work for them.
“Only time will tell whether Harry Redknapp will be a success.”
