Ronaldo is currently clubless following his tell-all interview with Piers Morgan, during which he took aim at manager Erik Ten Hag and other senior figures at the club.
United severed ties with Ronaldo on the eve of the World Cup, bringing to an end two spells at Old Trafford which yielded 145 goals in 346 appearances.
Former Uruguay striker Forlan played with Ronaldo during his first spell at Manchester United and he believes the Portugal captain is still very much loved in the red half of the city.
"It won't affect [his legacy], but obviously it wasn't the best [exit]," he said.
"The truth is that it was a pity, because we are talking about one of the best players in history, a great professional and a club that is an example.
"The fact that it's broken, it is a real shame. Because he, like other great footballers that were players at the club, were ambassadors of the club itself.
"In general, these kind of players have the chance to play where they want, but maybe not where they would prefer now, because of their age.
"Some clubs would love to have them, but today it is more difficult because clubs look more at numbers and age, and the teams start taking other decisions. But will have to see what motivates him, what he likes and which options of different clubs will be available for him."
