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The pair were sidelined in October, Nowell tearing a quad muscle and Jess with an injured toe.
While England international Nowell came back in December, Jess only returned in Exeter's Anglo-Welsh win on Saturday.
His comeback meant hair had to go, but Nowell opted to part with his signature rat-tail rather than his beard.
"It actually wasn't my idea, it was Jack's idea - people have been tweeting me saying 'hurry up and get fit because Jack's looking a bit scruffy," Jess told BBC Radio Devon.
"To be fair it's just a little thing that got us through the rehab - because it's a long old injury you need something like that to perk you up a little bit, and as a goal as well."
Exeter Chiefs wing Matt Jess says a pact with team-mate Jack Nowell, not to shave until they both returned from injury, helped him through his rehab.