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The Welshman said he felt lucky that he did not need surgery on a partially dislocated shoulder suffered in a crash caused by a police bike.
He hopes to use the 2017 Tour de France, from 1-23 July, to recover.
"I always knew I could get back into decent enough shape," Thomas told BBC Wales Sport.
"It was just a case of how good a shape I would be in."
The Team Sky rider was leading his team for the first time in Italy, but pulled out of the event five days after the crash with the injury having taken its toll.
He said: "Mentally it was as tough as it was physically. I took a week off after the crash.
"Where I dislocated my shoulder, a bit of the bone had come away with the cartilage, but luckily I didn't need an operation so I was just trying to get back into the best shape possible.
"I was feeling the best I ever felt in training before the race and doing the best numbers I had ever done before.
"It was tough to take mentally initially, but when you have another goal like the Tour de France it certainly helps to get over that disappointment."
Thomas has competed in seven previous Tour de France races, the first in 2007, but a decade later says he has lost none of his enthusiasm.
"I am as excited now as when I was picked for my first," he said.
"It's always exciting when you get the official nod, especially in a team like Sky, who are looking to win the race overall.
"When you look at the super strong squad that we have got, it's always nice to get picked.
"So I am looking forward to another lap of France. It's the biggest bike race in the world and the one I grew up watching.
"It's so iconic and the first thing you think about cycling. To be a part of it again is massive. But it's going to be tough."
Thomas is hopeful his Team Sky colleague Chris Froome can continue making British cycling history with a fourth Tour title.
"He has got a great chance," Thomas said. "His run up to the race has not been like previous years, but he is still in great shape.
"He has the experience and knows how to win the race and deal with all the outside pressures.
"We all have confidence in him."
Geraint Thomas says it has been "mentally as tough as it was physically" to overcome his crash at the Giro d'Italia in May.