Froome, a four-time winner of the race, will miss this year's Tour after sustaining serious injuries in a horrific crash during the recent Critérium du Dauphiné. The 34-year-old suffered fractures to his sternum and the C7 neck vertebrae, as well as his right femur, elbow and ribs after crashing during a recon of the stage 4 time trial.
Thomas, who is currently racing the Tour de Suisse, said the news of the crash had come as a "big shock" in his latest column for British magazine GQ.
"Hearing about any crash is bad enough, let alone when it's one or your close teammates and friends," he wrote. "I haven't spoken to Froomey yet, but I spoke to Wout [Poels], who was there with him, and Dan Martin, who was just behind him, and they said it was pretty scary. Someone crashing at high speed into a wall isn’t the best thing to witness.
"The doctors have said it's all going well, though, and they're hoping to move him over to a hospital near Monaco, near where he lives. Froomey has a long recovery ahead of him now, but by the sound of things it could have been worse. We're all lucky it wasn't."
Froome's absence will significantly alter the complexion of the race, and indeed the approach at Team Ineos. He and Thomas were set to share leadership, but now the Welshman becomes the main figure, even though Ineos have another potential winner in young Colombian Egan Bernal, who was set to lead the line at the Giro d'Italia until he broke his collarbone.
"The biggest implication for the team is that there’s now an extra space in the line-up. Chris Froome was always guaranteed a ride," Thomas wrote.
"From my point of view, it doesn't really change much – I've always just been trying to get to the race in the best shape I can be in and then compete. For the team, though, we're going into the Tour without one of the greatest riders ever. Tactically, we had a strong hand to play in the finale of the biggest stages so it’s a setback, but we're still strong as a team.
"We'll go into the race with me and Egan [Bernal] very much still in contention, looking to get the best result possible. I'll still be a protected rider, but it looks like we'll have one less leader and one more domestique. I don't know yet who that will be – there's a longlist of 10 to 12 riders and Sir Dave Brailsford will name eight from there. It's a decision that's not usually made until a week before the race, anyway."