SAN DIEGO (CNS) - A man accused of fighting with security guards after jumping onstage at last weekend's Taylor Swift concert at Petco Park -- injuring a member of the singer's security team -- pleaded not guilty Wednesday to felony assault and battery charges.

Christian Ewing, 26, was ordered held on $100,000 bail.

Deputy District Attorney Jessica Coto said Ewing hopped a fence during Saturday night's concert but was told by Swift's personal security guard, David Durkin, that he couldn't be in that area.

Ewing was handed over to Petco Park security and was being escorted out of the San Diego venue, but he escaped and ran onto the stage where Swift was performing her song "Style," Coto said.

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During a violent struggle to get Ewing off the stage, the defendant dropped his knee into Durkin's sternum, causing the security guard's ribs to pop up over his sternum, causing great pain, the prosecutor alleged.

Once Ewing was dragged off the stage, he gave police a false name, Coto alleged.

When asked why he went up on stage, the defendant replied, "I love that girl," referring to Swift, according to the prosecutor.

Coto said Ewing had several arrests in multiple states, an active warrant for a theft-related offense out of Florida, and a felony conviction for transporting drugs from out-of-state.

Judge Jay Bloom ordered Ewing, who faces four years in prison if convicted of the felony charges, to stay away from Swift and her security team, Coto said.

The judge scheduled Sept. 14 readiness conference and Sept. 16 preliminary hearing dates.