The ex-Ipswich Town defender was coach of the Galaxy at the time of Beckham's arrival from Real Madrid and now admits he, the club and the league were not quite aware of just how big the England international really was.
"I don't like the word 'circus' because it sounds like it was out of control and I don't think it was," Yallop said about Beckham's arrival.
"It was just that we had no idea just how huge David Beckham was. It caught us all by surprise.
"Now they handle things fine but we were all entering the unknown. The first four months were crazy, so many people at the press conferences. We weren't quite ready."
"Not having the best of teams and having a few injuries, including David, who hardly played for me - it didn't really go well," he added.
"When you look back, as a coach, it was tough - you're trying to make sure all the guys are focusing on the game.
"It was a fun time but the results on the field didn't show that. Now the buzz is over a little bit, he's been there a while now and it's calmed down and the team is better and more focused."
Yallop is now the coach of the San Jose Earthquakes who take on Beckham and the Galaxy in the final game of the regular season this weekend.