A thrown bobblehead doll of Omar Bravo, a Sporting Kansas City forward, struck Nielsen in the face in the 26th minute of his team's 3-1 victory over the Portland Timbers on Wednesday night.
"First I thought I walked into the post, then I realized I was a long way from the post," Nielsen told The Kansas City Star on Wednesday.
"I had a crazy headache. I was like, 'Oh my God, I need to lie down for a second.' Then I saw I was bleeding and was just waiting for them to come and fix it so I could play again."
After being attended to by trainers, Nielsen remained in the game.
Livestrong Sporting Park security apprehended two men who sat in the third row behind Nielsen's net.
Security cameras at the $200 million state-of-the-art facility were used to identify the suspects. It is uncertain whether the two men meant to hit Nielsen when they threw the dolls.
"We take this seriously," Rob Thomson, Sporting Kansas City vice president of communications, said in a telephone interview Thursday. "We've worked cooperatively with law enforcement personnel."
Thomson said Nielsen is fine and is preparing for the team's next game against DC United on Sunday. Thomson said the club has not heard an update from Kansas City, Kan., police about the suspects' status. He added the organization will work to prevent a similar incident in the future.
Thomson said the team will move forward with future promotional plans. He said safety remains a priority.
"We'll look into what can be done," Thomson said.
"This is an isolated incident, but safety is our primary concern. We'll discuss further promotions and what that entails.
"There have been countless bobblehead nights in Major League Soccer and around America and other countries. But we'll look into what we can do to make sure this situation doesn't happen again."
foxsports