The Octagon’s return to London’s O2 Arena is scheduled for March 17.
Zaleski (18-5), who won his last four bouts in the UFC, injured his left knee during a sparring session two weeks ago and thought he would recover in time to fight in London. The Brazilian fighter will avoid surgery, but won’t be cleared to train at least for 20 more days.
Marshman (22-7) has bounced between wins and losses since joining the UFC in 2016. The ex-Cage Warriors champion competed for the last time in October, losing to Antonio Carlos Junior.