He sat down in the boot of the GB team estate car and kept coughing.
Around him, his training partners, Movistar rider Alex Dowsett and Sky riders Ben Swift and Luke Rowe, gave their bikes back to the mechanic and walked into the hotel. Millar was still coughing. A two-hour ride with a coffee break halfway had provoked a cough that would have sent anyone to the doctor for strong medicine. It didn't sound good.
The previous day, Millar had spoken about his enthusiasm for the upcoming Tour de France start in Yorkshire, how his wife Nicole and his sons were flying over from Spain to see him race in his final Tour before his retirement.
"I shouldn't have started the time trial on Thursday, it was a bad idea, it wasn't going to do my health any good," he said. "But I sort of needed to start to show the team; if I hadn't started and said I wasn't healthy enough so close to the Tour, that wouldn't have been a good message to send out," he admitted.
During Sunday's 114-mile national championship race around Abergavenny, Millar missed the winning break and pulled out after 50 miles.
Stopping at the Team Sky bus, he dismounted and the hacking cough was back. He paused and looked up: "Riding a bike is not the way to cure bronchitis."
Still unsure about his selection for the Garmin Sharp Tour team, he was aware that his health issues would weigh against him. "Maybe we don't need to write about that though, eh?"
Somehow, though, word did get out and Millar's Tour place went with it.