Four-time Olympic equestrian show jumper Beezie Madden has withdrawn from the Tokyo Olympics.

Madden announced via Facebook on Friday that her horse Garant was not ready to compete after performing at the Nations Cup in Rotterdam. Garant was withdrawn from the competition after a shaky performance in the first round.

According to Madden, Garant is "healthy and sound, but just is not quite ready for what the Olympics would ask of him."

Madden, 57, is a four-time Olympic medalist for the U.S. show jumping team. She won back-to-back gold medals in team showjumping at the 2004 and 2008 Olympics, followed by a silver medal at the Rio Games in 2016. She also won a bronze medal in individual jumping in Beijing.

The full U.S. Olympic equestrian team is expected to be announced Monday.