The 38-year-old, who won the Tour of Flanders in 2017, was a non-finisher at both E3 Saxo Bank Classic and Gent-Wevelgem last week. He has struggled for form since the start of the season after his winter was dominated by rehabilitation from a knee injury sustained at last October's Tour de France.
He will miss Sunday's Tour of Flanders for the second year in a row - after the same injury ruled him out of last year's rescheduled fall edition - and it remains to be seen whether he returns for the Ardennes Classics later in April.
"With the team, I've decided to take a period of rest because things aren't going well at all. Things haven't been going well for several weeks now. We've taken the time to analyse everything we could, and the best explanation is a lack of mental and physical freshness," Gilbert said in a long statement.
"My idea is to have four or five days off the bike and then start training again gently. The Ardennes Classics are still possible, but it's still too soon to speak about specific dates. I want to feel 100 per cent in the body and the head so as to play a role in the finals. That's why I do this sport."
Gilbert believes his recovery from his knee injury is behind his malaise, and that his body has been crying out for rest.
He fractured his kneecap for the second time in his career when he crashed out on the opening stage of last year's Tour de France. He returned to racing just over two weeks later but had to abandon the BinckBank Tour and end his season when the pain resurfaced.
Despite backing off to the point where he lost significant muscle mass on his left leg, Gilbert admits he may have been too eager once again during the off-season. With the major career goal of completing the set of five Monuments at Milan-San Remo on March 20, he put himself through a heavy regime of training, together with visits to various specialists.
"I think this took an enormous amount of energy out of me during those months. The fact that the body had to heal itself took much more energy than we could have imagined and I think I'm now paying for all that effort," he said.
"After our analysis, I realise that at the team training camp in January I was, I think, still at least 20 or 30 per cent behind the rest of the group. I then had a period of doubt, especially because I was putting pressure on myself to be ready for Milan-San Remo. I worked hard to try and come back, and I made great progress after that camp, but maybe it was a bit too quick. Now I'm paying for it."
Gilbert revealed that the first time he rode with no pain in his knee was on March 19, the day before Milan-San Remo. Before that, he had already completed 19 race days.
Fifth place at Omloop Het Nieuwsblad was a strong result but Gilbert put it down to "experience rather than legs" while at the subsequent Paris-Nice he was "only capable of following wheels".
He finished Milan-San Remo in 72nd place before abandoning both last week's Flemish Classics.
"At the end of the day, not once have I been at my best this season. It's time to stop and that will allow me to turn the page," Gilbert said.
"I've reached a moment in my form where I'm not improving. I'm stagnating and I'm not managing to step up a level. Normally, each year after Tirreno-Adriatico or Paris-Nice I get stronger. Here, I've stayed at the same level, so the body is no longer accepting the workload and is overcompensating in other areas. When you reach that point, the only way to leave the body to work naturally is to rest."
Thank you for reading 5 articles in the past 30 days*
Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read any 5 articles for free in each 30-day period, this automatically resets
After your trial you will be billed £4.99 $7.99 €5.99 per month, cancel anytime. Or sign up for one year for just £49 $79 €59
Join now for unlimited access
Try your first month for just £1 / $1 / €1