Young looks set to start the European Championship playing off Danny Welbeck, with Rooney suspended for his country's opening two games.
Rooney has long been considered England's talisman but Young has threatened to wrest that mantle from his Manchester United team-mate in the last 18 months.
Young has now scored six times in his last 10 internationals since the end of 2010, with Rooney having found the net just twice in six games over the same period.
Downing and Young starred together for two years at Aston Villa, where the latter first found himself moved off the wing to a more central role.
Both players joined new clubs last summer and Liverpool winger Downing said: "He's tricky and finds himself in good areas and can nick a goal.
"He can find a pass, score a goal and maybe now we have another player to play in that role as well as Rooney."
He added: "You can see with the run of games he's had and scoring a few goals that his confidence has grown.
"He's a terrific player, a good lad and I personally like playing with him because we seem to be on the same wavelength.
"I think he's come into his own a bit and has the confidence he can do well in this team."
Downing, who is being tipped to start alongside Young in England's Euro 2012 opener against France on Monday, revealed he himself preferred to play in a deep-lying role.
He said: "When I first went to Aston Villa, he was on the left, I was on the right and you saw his ability to get good crosses into the box.
"I prefer to play in the hole, if I'm honest, and at Aston Villa when he went into the hole and I went out wide, I think we linked up quite well. Me, him and Darren Bent."
Before Bent arrived at Villa, Young and Downing played alongside James Milner, who has also been heavily tipped to start in midfield on Monday.
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There was brief concern over the Manchester City midfielder after he sat out England's visit to Auschwitz and the Oskar Schindler factory.
But the Football Association confirmed the 26-year-old was advised to stay off his feet after suffering blisters and were confident he would train on Saturday.
Apart from Jermain Defoe, who returned home following the death of his father, Milner was the only member of the England squad not to visit either Auschwitz or Schindler's factory.
He is also the only member of the squad to have played every minute of manager Roy Hodgson's first two games in charge.
Milner was one of nine players not to take part in full training, eight of whom are expected to play on Monday.
The FA were at pains to stress all the absences were planned after a tough session behind closed doors and were part of the individual players' rehabilitation programmes.
The respective visits to Auschwitz and Schindler's factory actually appeared to give more away about England's starting line-up on Monday than this morning's session.
Apart from goalkeeper Joe Hart, the longer trip to Auschwitz was attended by players not expected to be in the XI, while nine of those who went to Schindler's factory are in many people's predicted line-ups.
The morning's session had muddied the waters, with Rooney paired with Danny Welbeck and Young partnering Andy Carroll.
But that Downing was curling over crosses from the left - with Alex Oxlade-Chamberlain operating in a deeper position - may have been a genuine pointer towards the Liverpool winger starting against the French, although such is the subterfuge involved in top-level football these days, nothing can be taken for granted.
It was still welcome to witness England's new open-doors policy in action, despite the absence of nine players from the main session spoiling it slightly for the 3,500 invited guests.
John Terry and Steven Gerrard, who were amongst those who did pool and gym work, came out at the end to sign autographs.
The session was part of a concerted effort to be "good tourists" and avoid the negativity that followed England's World Cup exit in South Africa, when they were based at a remote location in Rustenburg.