Rooney has turned into an old head at Old Trafford this season as Sir Alex Ferguson has transformed the make-up of his team. Phil Jones, Chris Smalling and Tom Cleverley all accompanied Rooney to England's training base in Watford ahead of Friday's qualifier with Bulgaria in Sofia, and striker Danny Welbeck would almost certainly have joined them had it not been for the hamstring injury he sustained against Arsenal at the weekend. The question now is whether they can maintain their current impressive form across an entire season. It is not unknown for younger players to struggle for consistency but, having worked alongside such talent at close quarters for the last couple of months, Rooney is adamant it will not be a problem. "They could be key players at Euro 2012," he said. "They have done well for the Under-21s in the tournament just gone. "The manager (Capello) has recognised that and brought them into the squad. We didn't do much in training today but you could tell they were comfortable around the other players. "They know a few players here and have settled in quickly. Hopefully they will get a chance and do well." All four United players, including Welbeck, were part of Stuart Pearce's squad at this summer's Under-21 Championships. Jones and Smalling were two of only a handful to emerge with any great credit from a largely disappointing campaign. Yet Smalling did so at centre-half. Now he is scrapping it out with Micah Richards for the right-back role on Friday, after impressing Capello with his performances for United out wide. "He has done brilliant for us at right-back this season," echoed Rooney. "Phil Jones can play at right-back too, so the two of them can play in different positions. "During a tournament it is so vital for the manager to have that." Yet it is not just the youngsters who have impressed at United this season. Ashley Young has taken no time to become accustomed to his new surroundings following an £18million summer move from Aston Villa. Young scored twice in Sunday's annihilation of the Gunners and also claimed a couple of assists. It should ensure a starting place in Sofia - unlike against Switzerland in June, when Capello left Young out of his XI and then required the winger to get him out of trouble after England had fallen two goals behind at Wembley. "He is at home in the international set-up and has done well in his last few games for England," observed Rooney. "He has come to United, settled in really quickly, scored a few goals, had a few assists and has worked really hard for the team. "A lot of people don't realise how hard he works but he is a great player to have in the team." The same could be said of Rooney, of course. His hat-trick against Arsenal took him to five goals for the season, a far cry from the difficulties he endured 12 months ago, which followed on from a dismal World Cup experience in South Africa. "It is always great to be in good form and scoring goals," said Rooney, who has scored just once for his country in two years. "Hopefully that form can continue over the next two games. "I am looking forward to getting back playing for England, doing well and getting the points we need." Although England have never lost to Bulgaria, the pressure is on this weekend because, unless the Three Lions come away with maximum points in Sofia, they will suddenly find themselves having to win their final match in Montenegro next month, knowing the hosts will still have a game left. Certainly a repeat of last September's results, when England slammed four past the Bulgarians at Wembley before crushing Switzerland in Basle, would be very handy at the start of a double-header that includes a visit from Wales on Tuesday. "Hopefully we can recreate that momentum," said Rooney. "I am sure Bulgaria away will be a good atmosphere. "It will be difficult to come away with three points but that has to be our aim. "Wales are a good team, but you would like to think we have enough to beat them at home. "Hopefully we can come out of these games with six points."