The club captain remained on the substitutes' bench all evening, despite the match going to extra-time and central striker Zlatan Ibrahimovic having to go off with injury late in the game.
Anthony Martial came on in place of the Swede with United having to rely on Marcus Rashford to score the crucial goal that took them through to the last four.
And with Rooney linked with moves away from the club, with little game time this season, Keane thinks this could the record scorer's last year at Old Trafford.
He told ITV: "In terms of the bigger picture I’d have thought that’s the end of Wayne at Manchester United.
Read the full article on eurosport.co.uk: Keane: It's the end for Rooney at United... he must be fuming