Edinson Cavani has been a long-term target for Massimiliano Allegri's side but Goal.com exclusively revealed last Thursday that Juventus could pull out of a deal for the Napoli forward after growing frustrated with the potential length of negotiations.
But Fonseca believes his former side should scrap plans to land Cavani this summer and instead opt for his Uruguay strike partner from Liverpool.
"Suarez is more powerful and deadly; Cavani more agile. Recently, both have been proving themselves as lethal finishers in the area. Juventus would be making a good choice by signing one or the other," Fonseca told Tuttosport.
"Suarez and Cavani would fit easily into the Juve system: they are mobile forwards with great goalscoring instincts. There isn't a €20 million [£16m] gap between them in terms of their value and, of the two, I'd prefer to see Suarez go to Juventus.
"Signing either player would be difficult, but Juve should make a great effort to sign one of them. Uruguayans are, except in very rare cases, always a success in Italy and the pressure of playing for a big team is not a burden for us."Suarez joined Liverpool in January 2010 for £22m, and is contracted to the club until the summer of 2016.