Justin Gatlin, a U.S. sprinter, will be forced to end his season early after being admitted to the hospital with a fever and stomach pains.

Gatlin took home the bronze medal at the London Olympics this year for his 100-meter run and was scheduled to run in the Athletissima event in Switzerland tomorrow, but because his condition hasn’t improved he will be unable to compete alongside Usain Bolt.

Organizers of the event issued a statement about Gatlin’s condition, saying: “His situation has not improved. Justin Gatlin has taken the decision to return to the USA, withdrawing from the meeting in Lausanne as well as ending his season.”

Because Gatlin was banned from the games from 2006 to 2010 on a doping charge, some are wondering whether or not drugs have played a part in this latest development.