The former "Law & Order" star has been portraying Detective Joe West on the DC Comics TV adaptation since its launch in 2014, but the 49 year old has had to temporarily step away from the show.
According to TVLine, Martin suffered a back injury during a filming hiatus, and has since had to shoot the majority of his scenes for the current season five sitting down.
"Jesse Martin is taking a medical leave of absence from 'The Flash'," show officials tell Entertainment Weekly.
"We wish him a full and speedy recovery and look forward to his return as Detective Joe West."
It's not clear when Martin will return to the small screen, but producers of the "Arrow" spin-off plan to address his period of leave in a future storyline.