Suarez is set to play UEFA Champions League football at Anfield next season after scoring 29 goals to put the club on the verge of their first Premier League title in 24 years, but it has not prevented talk of a possible off-season switch.
His goalscoring exploits have attracted interest from Manchester City, who are reportedly preparing a big-money offer, though director Ian Ayre was quick to play down a potential departure in an interview with BBC Radio Five this week.
However, Forlan, who scored 17 goals during his three-season spell at Old Trafford, believes a move to the red side of Manchester would be the best decision for his career.
That is despite United languishing in seventh position, seven points adrift of the final Champions League spot.
"We spoke a few days ago," the 34-year-old Cerezo Osaka striker was quoted as saying in Brazilian sports paper Lance!.
"He asked me if I think he should stay at Liverpool.
"All I told him was to think about going to Manchester United. I know he loves Liverpool, the fans and the city.
"But I think the best thing for his career would be to move to Old Trafford."
If Suarez was to make the switch to Old Trafford, he would be the first player to transfer between the two clubs since Phil Chisnall in 1964.
Former United defender Gabriel Heinze came close to signing for Liverpool in 2007 before he eventually joined Real Madrid.
