Beckham joined Milan on loan last January until the end of the Serie A campaign and is set to rejoin the club this January.
Seedorf told Corriere dello Sport: “Beckham can certainly help Milan. I would be happy if he returns.
“We became friends during his loan spell here, and for that reason it would make me happy to see him return.
“I have been in contact with him several times and, if the deal can be done, it will be good for Milan and for him too because it would be a pity not to see him in the World Cup.
“He is a player who has already given an important contribution to Milan and I am convinced that he would continue to do so if he returns to Milan.”