It was a sound hypothesis given that Thomas came into the Tour as the Critérium du Dauphiné winner and had not put a foot wrong during the opening nine days of racing. The Welshman – a superior climber to Van Avermaet on paper – started the first Alpine test 43 seconds in arrears, but ahead of the other GC contenders.
However, a gutsy ride from Van Avermaet – in which he infiltrated the day's break and even extended his GC lead to over two minutes – ensured that Thomas would remain second overall and therefore miss out on the yellow jersey.
Team Sky's tactics on stage 10 were clear for all to see. They kept the break at a respectable distance but never once set a pace that suggested that they wanted to propel Thomas into the lead. Their objectives at this year's Tour are based on long-term success – and that means yellow in Paris.
The British team set a fast but not unmanageable pace on the final two ascents before the finish at Le Grand-Bornand, and while a handful of GC prospects struggled after Monday's rest day, the stage ended in a relative stalemate.
"I said before, it's the Tour de France, so you can't have the jersey just because you want it. Fair play to Greg. He got himself in the break, and that’s what he did last time he had the yellow jersey [in 2016], so we expected it," Thomas told Cyclingnews as he freewheeled to the Team Sky bus after the stage.
With a headwind on the final climb, and with Team Sky setting the pace, there were few sparks of action, with the majority of the overall contenders content to save their power for the next two mountain stages.
Only Daniel Martin (UAE Team Emirates) was willing to roll the dice with a late attack on the final climb. The Irishman drew a response from Team Sky, and was shut down as the race crested the summit and began the final descent to the finish.
"I expected someone to try on the last climb. Michal Kwiatkowski was setting a decent tempo, and there was a headwind, so maybe some people were put off by that. But tomorrow, for sure, it's going to hit the fan," Thomas said.
"Everyone was a bit unsure – or I was – how I was going to be. You expect the worse and hope for the best, but I was expecting someone to go. No one did, but there are still two more days. When Dan went, we had to squeeze and close him. We were in control."
With back-to-back stages in the Alps still to come, and with Movistar's trio of leaders promising to attack before Team Sky can gain the yellow jersey, the race is well poised.
Thomas doesn't appear to be feeling the pressure at this stage, but he will be only too aware that taking yellow in the Alps will lead to more questions surrounding Team Sky’s leadership. Whether those questions will still be relevant after Alpe d’Huez, on stage 13 on Thursday, remains to be seen.
"I'm used to leading at week-long stage races," Thomas continued. "Froome is the leader here, so there's no pressure on me. It's a bonus for me to be up there, and hopefully I can be there for as long as possible.
"Tomorrow [Wednesday] is a harder day. It's a short stage, and they might try to go early, but it's a mountain-top finish, so it's going to be selective. Then, the day after, we go up Alpe d’Huez, and that's going to be even harder."