With some kind of sickness seemingly to blame, Kittel has been taking the time to try to find the root of what's been making him unwell and unable to race at the highest level.
"While I will be criticised once more, I'm looking for reasons behind all of this," Kittel said after quitting the BinckBank Tour.
Although he went on to start in his home race, once again Kittel was forced to abandon the Deutschland Tour having only ridden stage 1, and said that he needed "to get a full health check now to know what is going on".
Kittel has won only two races so far this year – both of them stages at March's Tirreno-Adriatico. His new team has also failed to fire, with Katusha taking just five victories to date in 2018.
It's all in stark contrast to Kittel's 2017 season – his last with Quick-Step Floors – when he won five stages at the Tour de France, and finished the season with 14 victories.
"Unfortunately for precautionary reasons, I won’t start in the Tour of Britain on Sunday," he said in a team press release on Wednesday. "In my current situation, it makes no sense to race. I have to wait for the results of further examinations. The risk would be too high.
"The Tour of Britain would have been one of my highlights in the second half of the season. I have wonderful memories of 2014: not only of my two stage wins at the Tour de France Grand Départ," Kittel said, remembering when he won the Tour's opening stage from Leeds to Harrogate and stage 3 between Cambridge and London, "but also my double stage wins at the Tour of Britain are well remembered.
"The British are an enthusiastic and competent cycling community. It's a pity not to be able to stand at the start line."
While Kittel is unable to race, the Katusha-Alpecin line-up for the eight-stage race sees the return of Tony Martin, who crashed out of the Tour de France in July with a spinal fracture. The German had hoped to ride the Deutschland Tour but had to be cautious about his comeback, explaining that any subsequent crash on his back could have more severe consequences.
Katusha-Alpecin will also be led by home rider Alex Dowsett, a fellow time trial specialist. There is no individual time trial on this year's route, but there is a team time trial, though the uphill nature of the Lake District course will tip the balance away from Katusha.
Also on the team's roster are Nils Politt, Mads Wurst Schmidt, Dmitry Strakhov, and Rick Zabel.