Beckham has had the cyst for six weeks and Saturday's treatment, which will prevent him from training for two days, was timed to coincide with Sunday's day off and Monday's flight to Portugal for Euro 2004.
"I can guarantee you it's not a problem," Eriksson said after Beckham completed 45 minutes and then had a warm-down during halftime in England's 6-1
"It was decided two days ago that he should have an injection. It was better to do that after the game because he has to rest two days, then he's ready to practice on Tuesday.
"He did everything for 45 minutes and after that he did another session of 10-15 minutes," Eriksson said. "He has absolutely no problem."
England start their Euro campaign in Portugal against holders France next Sunday, before going on to face Switzerland and Croatia in their remaining games in Group B.