In his first appearance since United’s 1-1 draw against Swansea, 48 hours before Christmas, Rooney struck after just nine minutes to earn the Reds a fourth round tie against Fulham.
But Rooney also squandered a chance to put the game beyond doubt when he sent a penalty kick sailing over the bar on 79 minutes. His failure to find the net from 12 yards made for a nervy final 10 minutes, as West Ham pressed for an equaliser that, thankfully, never came. Instead, United progressed to the competition's next round and will now host Fulham – and welcome back Dimitar Berbatov to Old Trafford – on Saturday 26 January (17:30 GMT).
Against West Ham, Sir Alex made 10 changes from the side that beat Liverpool three days earlier, with only right-back Rafael keeping his place. West Ham boss Sam Allardyce also utilised his full squad, opting for youth over experience in a number of positions.
Nani and Anderson were welcome sights in the Reds’ XI following lengthy lay-offs, while Rooney enjoyed his first action in three weeks. The England international marked his return to the side with the game’s opening goal. But although the striker applied the last touch, he owed the ease of his finish – a tap-in from inside six yards – to Javier Hernandez’s unselfishness and a clever, defence-splitting Anderson pass.
The ball sent the Mexican clean through and he would have been entitled to try and beat Jussi Jaaskelainen himself. Instead, Hernandez looked up and calmly rolled the ball across the area, leaving Rooney with an open goal.