McCloskey will win his seventh cap since making his debut in 2016. A superb season so far has put him next in line to Henshaw, his centre partner on Saturday Garry Ringrose (27) and the suspended Bundee Aki (32) ahead of next year's World Cup.
Leinster utility back Jimmy O'Brien (25) could win his first cap after being added to the bench for the opening test of Ireland's November series.