The Galaxy have not yet replaced Beckham with another big-name, big-money player but they have been linked with England stalwart Lampard who looks likely to leave Chelsea when his contract expires at the end of the season.
"I am sure they have someone in the pipeline. I think it is important for the team to get big-name players in and if we get Frank it will be good - he's been on fire," Ireland striker Keane told Reuters in an interview.
He netted in Chelsea's 4-1 victory over Wigan Athletic in the Premier League on Saturday and grabbed the winner in England's 2-1 friendly triumph over Brazil on Wednesday.
"It's not really hard to understand," said Keane. "It's very simple, he loves playing the game.
"Why would he not go to Paris? They are top of the league, they have a great manager [Carlo Ancelotti] who he knows very well after playing for him on loan with AC Milan. It makes sense regardless of all the other stuff.
"People are always going to question it because he is such a big figure but I know him personally and I know he just loves playing the game. What's wrong with that?" added Keane.
"He still has passion for the game and he is still a quality player," said the Irishman. "He is going to a team that is probably going to win their league.
"It's not a bad place for him to be - hopefully he wins that league too because he has won in Spain, England and America. I hope he does it."
