Following an indifferent US tour where results are concerned, United turned on the style winning 7-1 in front of a near full-house at the impressive Aviva Stadium.
Ahead of the game, the fans had been promised both Rooney and Vidic would play some part and the supporters were not disappointed. Rooney didn't manage to get his name on the score-sheet-but he looked to be in reasonable condition following what was a disappointing season end and a World Cup to forget.
The Sun published photos of Rooney revelling into the early hours in Manchester last weekend and according to reports Ferguson was not best pleased. In the wake of what amounted to a Dublin walk in the park, comes the much stiffer challenge of Chelsea this Sunday in the Community Shield at Wembley. The United manager has promised to give Rooney more playing time in a bid to regain his sharpness, but it might take a few games before we see last season's top goal-scorer back to anywhere near his lethal best.
Vidic looked to be in good nick in Dublin, this time alongside Chris Smalling and it looks as though this will be Ferguson's preferred central defensive partnership, especially if Rio Ferdinand does not regain full fitness.
Ferdinand has been plagued by a succession of injuries and so chances are, from now on, we can expect to see him in cameo roles. The 'England captain' is likely to be a member of the supporting cast rather than one of the stars of the show from now on.
Smalling likes to get forward and it will be interesting to see how he fares against Chelsea this weekend - first and foremost he needs to be a solid defender and if he can forge a good understanding with Vidic at the back, it might well prove to be shrewd business by Ferguson, but, the former Fulham player will be judged on his defending and not what he does in United's opponent's half of the pitch.
Vidic spoke to the media after the game in Dublin and everyone connected with United will have been especially relieved to hear the Serbian defender confirm he's going nowhere this summer following weeks of speculation about his future.
While the Airticity friendly was a typical pre-season workout, it was another opportunity to improve fitness and to give the new boys more time on the pitch with their new team-mates.
It was somewhat surprising to see Michael Owen start, given he didn't go on tour to the US, but the manner in which took United's scond goal suggested he's regaining his sharpness in front of goal and that must bode well for what lies ahead.
Owen was replaced at half-time by the player who could go on to give Rooney a run for his money by eventually becoming the new fans' favourite and Chicharito wasted no time in adding United's third goal of the night with more or less his first touch following another good ball in from the right by Valencia. Chicharito has quick feet and as well as a goal-scorers instinct and from the brief glimpses we've seen so far he could go on to do very well this season.
Valencia stretched United's margin to four with a simple goal and then Park added his second of the night after he'd opened the scoring with a fluke in the opening minutes. The South Korean's second effort was an altogether more impressive goal as it was expertly curled into the top corner giving Rogers no chance.
Jonny Evans, who was playing left-back made it six-nil with a well directed header, but the biggest cheer of the night was reserved for Dave Mulcahy who converted a late consolation goal - however, according MUTV match summariser and United legend, Paddy Crerand, it was offside...
Nani ended the scoring from the penalty spot after Chicharito had been fouled.
Ferguson will be absolutely delighted with United's progress this summer thus far and the new players appear to be bedding in well. The one glaring weakness in the United squad is the lack of genuine proven quality in central midfield. United need to find a replacement for Paul Scholes and failure to do so could yet prove to be costly.
Reports claim United are hoping to sign Gremany's star of the world cup, Mesut Ozil, on a free next summer; if true, this looks like a gamble given Jose Mourinho is known admirer - many United fans would surely agree it's better to snap up the Werder Bremen star now rather than risk losing him.
It will be interesting to measure United against Chelsea at Wembley especially in midfield, because the West London club are the bookies favourites to be champions again. It is difficult to argue with the bookmakers looking at the two squads, but with Vidic staying, United will be in a shout providing the engine room can cope and supply the likes of Rooney and Chicharito.
Airtricity League XI 1-7 Manchester United
Dave Mulcahy 79 Ji Sung Park 13, 63 Michael Owen 25
Chicharito 47, Antonio Valencia 60
Johnny Evans 69, Nani 82
Airtricity League XI: Gary Rogers (St Patrick's Athletic); Brian Shelley (Bohemians), Gavin Peers (Sligo Rovers), Ken Oman (Bohemians) Conor Powell (Bohemians); Ryan Guy (St Patrick's Athletic), Paul Keegan (Bohemians), Shaun Williams (Sporting Fingal), Killian Brennan (Bohemians); Joseph Ndo (Sligo Rovers), Paddy Madden (Bohemians).
Subs: Alan Kirby (Sporting Fingal) for Brennan (h/t), Conor Kenna (St. Patrick's Athletic) for Peers (54), Karl Sheppard (Galway United) for Madden (64), Richie Ryan (Sligo Rovers) for Williams (64), Ger O'Brien (Sporting Fingal) for Guy (70) Dave Mulcahy (St. Patrick's Athletic) for Ndo (70) Ger Doherty (Derry City) for Rogers (70).
Manchester United: Tomasz Kuszczak (Ben Amos 65); John O'Shea, Nemanja Vidic, Chris Smalling, Jonny Evans; Antonio Valencia, Michael Carrick (Darren Fletcher 37), Darron Gibson, Ji Sung Park (Nani 65); Michael Owen (Javier Hernandez h/t), Wayne Rooney (Dimitar Berbatov h/t).
Referee: Alan Kelly (Cork).
Venue: Aviva Stadium, Dublin
Attendance: 49, 861.