Geraint Thomas ought to be on the podium at the end of this year's Tour de France, but it will be Team Sky who decide on which step he will be standing.

That is the view of Welsh professional cyclist Gruff Lewis, who will be part of the Seiclo commentary team bringing live coverage and highlights from every day of this year's Tour on S4C, starting on Saturday.

Thomas, who trains with Flintshire cyclist Rob Partridge, wore the yellow jersey during the opening week of last year's memorable renewal of Le Tour, and the Cardiff-born 32-year-old is fancied to challenge for top honours in the Grand Tours if given the nod by Sky team boss Dave Brailsford.

Gruff, who represents Ribble Pro Cycling, said: "If you showed me a photo of the podium on the Champs-Élysées at the end of the race, I would not be surprised at all to see Geraint standing on it, but for him to win, the tables will need to turn at Team Sky. Chris Froome would have to work for Geraint, and that hasn't happened before.

"Team Sky say they are going to play both options for the general classification, but if they attack each other in the mountains, that would work in the favour of the other teams. I would like to see Geraint lead. By winning the Critérium du Dauphiné, he showed that he is as strong as Froome at the moment. He is flying."

The participation of four-time champion Froome in this year's race was confirmed just days before the Grand Depart. After a drugs test last year showed an adverse reading of Salbutamol, a legal drug commonly used to combat asthma, a nine-month investigation by cycling governing body, the UCI, was formally closed on Monday with no further action to be taken against the 33 year-old.

Despite the announcement, Gruff believes Froome may be in for a hostile reception from the crowds lining the roads.

"Dave Brailsford has had a hard time in the press over the past few months and Chris got some stick in the Giro d'Italia, with spectators dressing up as doctors and carrying a giant inhaler," he said.

"I think the fans on the mountains will give the team a tough time. Things could get quite nasty for the team, including Geraint and Luke Rowe, although I hope they don't. Froome has maintained his innocence all along so I'm sure he will just get on with it regardless."

With iconic climbs such as Alpe d'Huez and Col du Tourmalet returning to this year's race route, there will be no shortage of flashpoints.

"The team trial at Stage 3 will be important and everyone will have to pull their weight," added Gruff, from Aberystwyth. "Stage 9, to Roubaix, will have lots of cobbles, so that will be interesting. The penultimate stage, stage 20, is a long individual time trial and that could work to Froome's advantage. The third week is where the race is won and lost and for those who raced in the Giro, this could be where their tiredness will show. We'll see. It's a fantastic race and one big game of chess."

Joining Gruff in the commentary box will be Wyn Gruffudd, John Hardy, Dewi Owen and brothers Rheinallt and Peredur ap Gwynedd, with Rhodri Gomer presenting the coverage.

Seiclo: Le Tour de France

Live coverage and highlights

Starts Saturday, 7 July, 2.00 and 10.00, S4C

Available to watch on-demand at, iPlayer and other platforms

A Sunset+Vine Cymru and Tinopolis co-production for S4C