Suarez, who has scored 29 goals in 28 Premier League matches for the Reds so far this season, moved to the current Premier League leaders from Ajax for a sum of £22.8m in 2011.
However, Forlan tried to tempt his Uruguay teammate to make the move to Old Trafford instead.
"We're close and we get on well," Forlan is quoted as saying by the Liverpool Echo. "He's polite and keen to learn, always asking me questions and for advice. I like how he feels he can turn to me in good and bad moments.
"Like when Liverpool made him an offer. Of course, I told him he should join Manchester United, but I also spoke well of Liverpool and their history.
"I told him how, after I'd scored for Atletico [Madrid] at Anfield to knock them out of the Europa League, their fans applauded me. He loves playing at Liverpool. He likes the Premier League – and the fans love him because he's a striker's striker."
Forlan spent three years at United, scoring 10 goals before moving on to Villarreal.