Yates, who placed ninth in 2015 and won the GP Industria & Artigianato on Sunday, says, "my numbers are good."
Thomas and Yates are the top British contenders with Steve Cummings (Dimension Data) in the seven day race from the shores of Tuscany east to the Marche region. They face an all-star cast with Nairo Quintana (Movistar), Tom Dumoulin (Sunweb) and Vincenzo Nibali (Bahrain-Merida).
"We'll see, prep is the same as always, my numbers are good, but there's always this pesky time trial in the last stage. It's only a 10-kilometre stage, but I always seem to lose absolutely loads of time," Yates told Cycling Weekly.
"We'll see, I had a bit of bad luck last year when they cancelled the mountain stage. That was a bit of a waste of time."
Orica could take an early advantage in today's 22.7-kilometre time trial in Lido di Camaiore. Yates would then want to strike early, in the mixed stages and the 16.1-kilometre summit finish, and gain an important buffer before the final stage in San Benedetto del Tronto.
"I'm in good in good contention," he added. "If I can try something, I'll try to get some time early."
Yates just returned from two weeks at altitude in Sierra Nevada. He immediately won the GP Industria & Artigianato.
Thomas, like Yates, is using Tirreno-Adriatico as a lead-up to the Giro d'Italia, May 5 to 28. He trained for two weeks at altitude with Chris Froome in South Africa and last raced in Australia's Tour Down Under in January.
"This is obviously my first race in a while, I'm looking forward now," Thomas said. "I'm watching a lot of racing on TV and every race, I'm say, 'I wish I was there' It'll be nice to finally get the number on my back.
"I will try to get the best I can, between myself and Landa, hopefully one of us can produce the goods and take the win."
Thomas last raced Tirreno-Adriatico in 2009 when he rode with team Barloworld. With Mikel Landa this year, the duo will prepare for their two-pronged Giro d'Italia attack.
"The main guys for the Giro are here, so it'll be a good test for everyone," Thomas said. "Saying that, a lot can still change from here until the start of the Giro."
Yates will race the Giro d'Italia with twin brother Simon for the first time after placing fourth in the Tour de France and winning the young rider classification in 2016.
Orica decided to send its Colombian Esteban Chaves, second in the 2016 Giro, to race the Tour this year.
"It's a joint decision," Yates said. "The Giro's a new race for me after doing the Tour for two years now. It's a new challenge.
"It's just a bit more unpredictable. There are always the top guys, then you have these climbers or breakaway guys with a lot more unpredictable and they want to get up there an cause some carnage. I reckon that kind of racing will suit me more, but we'll have to wait and find out."
Yates will race in the Volta a Catalunya and in the Ardennes Classics next, and perhaps will train at altitude another time. He said, "The Giro is still a long way off."
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