The Bahrain-Mclaren sprinter was part of the breakaway during the 232.5 kilometres race between Ypres and Wevelgem and went on to finish 74th.
Speaking to Sporza in a post-race interview, an emotional Cavendish said: “That’s perhaps the last race of my career now.”
Cavendish, who has won 30 stages of the Tour de France and is considered one of the best sprinters in the event’s history, was left out of Bahrain McLaren’s squad for this year’s Tour.
The 35-year-old’s contract with the team is set to expire at the end of this year but talks have been ongoing for a one-year extension.
Cavendish’s comment hinting at retirement came as a surprise because he is committed to line up at Scheldeprijs on Wednesday.
Cavendish won the Scheldeprijs race on his debut in 2007. He followed up with victories in 2008 and 2011 before finishing second in 2013 and 2016.
Bahrain-McLaren boss Rob Ellingworth sought to clarify Cavendish's comments in an interview with Eurosport's Orla Chennaoui.
"We are still talking," Ellingworth said. "Obviously due to the situation this season, everything is happening later in the season as well."
“So, recruitment is happening later, we are still not complete for next year. We have only recently secured finances going forward. Mark, like many other riders, will be out of contract, but discussions are going on.
“Mark is getting to the age where he is probably thinking about post-cycling, and he has not had the successful season he would have hoped for.
"I have not spoken to him about that in the last few days so let’s see, but the next few weeks will be critical for all riders out of contract.”