Cavendish was a doubt to ride the Tour after spending a huge part of the season out with Glandular Fever. He raced at Tirreno-Adriatico and Milan-San Remo in March, but only returned to competition in June at the Tour of Slovenia.
The 32-year-old Manxman took part in the British National Championships road race on Sunday, but wasn't able to contest the win, finishing out of the time limit in the near 200km race.
But it appears that Cavendish has done enough to prove fitness for the Tour, where the sprinters will get opportunities on nine potential stages of the race.
The former world champion admitted in the team statement on the squad that if it wasn't the Tour, the decision to compete probably would have been different.
"As has been widely reported, it’s been a difficult few months for me on the back of the illness that set me back earlier on in the season," Cavendish said.
"Despite this setback and my lack of race time I’ve worked incredibly hard both to ensure I could firstly recover from the illness as well as then aiming to build my fitness up as much as possible in order to start the Tour.
"If I am being totally honest, had this not been the Tour de France we may have collectively taken a different approach with regards to my inclusion but I feel that I owe it to myself, the team, our sponsors and most importantly to the Tour itself given its history and everything that it stands for – as well as the emotional attachment I have for it – to give it my best and to put everything I have in to trying to help the team."
Fellow Brit Cummings will also take to the start in Düsseldorf on Saturday, having had his own injury troubles after crashing heavily at the Tour of the Basque Country in April.
This will be Cummings' third consecutive Tour start, having taken stage wins in both the 2015 and 2016 editions of the race.
The 36-year-old said he needed to prove himself during the National Championships last week, and did just that by winning the time trial crown on Thursday and the road race title with a solo breakaway on Sunday.
Cavendish and Cummings will be joined by fellow Brit Scott Thwaites, who makes his Tour de France debut.
Meanwhile, Cavendish will be supported by an experienced sprint train of Bernhard Eisel and Mark Renshaw, while Edvald Boasson Hagen will provide another option in the sprints.
Belgian Serge Pauwels, who won the Tour de Yorkshire overall this year, will likely be utilised in breakaways as Dimension Data focus on stage wins at the Tour.
Dimension Data squad for 2017 Tour de France: Mark Cavendish, Steve Cummings, Edvald Boasson Hagen, Bernhard Eisel, Mark Renshaw, Serge Pauwels, Reinardt Janse van Rensburg, Jaco Venter, Scott Thwaites
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