Simone Biles and the US women’s gymnastics team unexpectedly struggled in Sunday’s qualifiers — and the four-time gold medalist is beginning to feel the pressure.

“It wasn’t an easy day or my best but I got through it,” Biles wrote in an Instagram post Monday morning. “I truly do feel like I have the weight of the world on my shoulders at times. I know I brush it off and make it seem like pressure doesn’t affect me but damn sometimes it’s hard hahaha! The Olympics is no joke!”

The Americans entered the Games as odds-on favorites, touted as perhaps the best gymnastics team in history. Yet by posting a 170.562, the US squad only managed the second-best cumulative score in qualifying, with the team representing the Russian Olympic Committee finishing more than a point ahead at 171.629.

Biles contributed to her team’s struggles with a slew of uncharacteristic errors. In the floor routine, she finished in second place after falling off the mat and going out of bounds following a tumbling pass. She finished seventh in balance beam after requiring extra steps to finish.

Biles, though, still finished first overall for the all-around competition. On Tuesday, she’ll have a chance to start anew amid mounting pressure in the finals, where she will compete in all four individual events: balance beam, uneven bars, vault and floor exercise.