Chris Froome and Sir Bradley Wiggins have been selected in separate Tour de France warm-up races this month in the clearest indication yet that Wiggins will not line up for Team Sky in Yorkshire on July 5.

Wiggins became the Tour's first British winner in 2012 and was a year later succeeded by Froome, who will lead Team Sky in the 101st Tour, which begins in Leeds, after establishing himself as the British squad's lead rider.

Froome will defend his title in the Criterium du Dauphine, a prestigious Tour warm-up Wiggins won in 2011 and 2012, from June 8 to 15, with Wiggins at the Tour of Switzerland from 14 to 22.

Froome is joined by Richie Porte, Vasil Kiryienka, David Lopez, Mikel Nieve, Danny Pate, Geraint Thomas and Xabier Zandio in the eight-man Dauphine squad, with all seven likely to accompany him at the Tour, leaving space for one more rider.

The nine-man Tour line-up is expected to be confirmed after the conclusion of the Swiss race by Team Sky principal Sir Dave Brailsford, who was tight-lipped on Wiggins' possible Tour inclusion last month.

The June line-ups come after publication of Froome's autobiography, The Climb, which may have reignited suggestions of a feud between the pair, who last raced together for Team Sky in February 2013 at the Tour of Oman and for Great Britain at last September's woeful Road World Championships.

After a sub-standard 2013, Wiggins is in fine form.

The 34-year-old won the Tour of California last month, just weeks after placing an impressive ninth in the one-day classic Paris-Roubaix, held over the cobbles of northern France which will feature in a key fifth stage of this year's Tour.

Chris Boardman, a previous Tour leader, believes Wiggins deserves to be selected on merit and that Brailsford will manage any possible issues over squad cohesion afterwards.

"Knowing Dave he'll do the best thing for performance and deal with all the politics," Boardman told Press Association Sport at Halfords' Summer of Cycling launch.

"Just to be in the top 10 (of Paris-Roubaix) says 'I could've won this race'. That was pretty damn cool.

"He's performing in the mountains at the moment, so I think he'll get on the team."

Wiggins has vowed to ride in support of Froome, but that is where Boardman questions Team Sky's approach, as Wiggins is to lead Team Sky in Switzerland, rather than work for another rider.

"They're not practising it," Boardman said.

"It's dress rehearsal on opening night if you're not careful. You're going to find out if someone can do a whole new role. That's the big unknown.

"But for us watching, whatever Brad does it will be a story.

"And that's exciting, that's why you like following him. You don't know what it's going to be, but it's going to be a story."

Wiggins is supported at the Tour of Switzerland by Joe Dombrowski, Christian Knees, Luke Rowe, Dario Cataldo, Philip Deignan, Ben Swift and Pete Kennaugh.