Bos was withdrawn from the Vuelta a Espana squad on Friday when pre-race medical tests showed that his cortisol levels were too low. He has already returned to his home in Monaco.
His only comment so far came Saturday on Twitter. “Broken man right now. Instead of racing tonight I fly back home to rest. Incredible. Good luck to the boys of @TeamBelkin”.
“We do no know the cause and Theo has no idea. Now we will see together how this can be,” Belkin team manager Richard Plugge said to the Dutch newspaper De Telegraaf.
Bos would have been allowed to start in the Vuelta under UCI rules, but the Dutch team is a member of the MPCC ((Mouvement Pour un Cyclisme Credible). The MPCC requires that riders whose cortisol levels are too low cannot race.
There are several reasons as to why the levels may be so low. "In ninety percent of cases, the too-low cortisol levels are due to use of cortisone. But there may be another reason underlying that we do not know,” MPCC director Roger Legeay told De Telegraaf.
"These are our rules and we adhere to them," Belkin spokesman Leon Brouwer told Gelderlander.nl.
Cyclists may use cortisones if they have a TUE (therapeutic use exemption). But Bos does not have one, nor does he need one, the team said.
His most recent race was the Eneco Tour, which he abandoned with saddle sore problems. However, the team said, he was given no medication in the lead-up to the Vuelta. “”Because then we would not have brought him here,” Brouwer said.