The Blues striker has become embroiled in a heated debate regarding his future at Stamford Bridge, with the riches on offer in the Chinese Super League said to have turned his head.
He played no part in a 3-0 victory over Leicester City on Saturday, with his absence put down to a back complaint.
Speculation regarding an imminent exit refuses to go away, though, with the winter transfer window open and Chelsea having already seen Oscar and John Obi Mikel leave Stamford Bridge for Asia.
Scholes saw Ronaldo and Rooney caught up in similar storms during his time at Old Trafford, with the latter twice requesting a transfer while the former completed a then record-breaking switch to Real Madrid.
He insists that he never discussed the matter with those in question, with it up to individuals to decide their own fate.
Asked on BT Sport whether he spoke to Rooney and Ronaldo during periods of uncertainty, Scholes said: "No, not one bit. Why?
"They're old enough to make their own minds up. If they don't want to play for the football club any more, so what?
"My job on a Saturday afternoon - and a Tuesday/Wednesday night - was to go out and try to win the game with my team-mates.
"Whoever I'm playing with - doesn't matter who it is. I don't care as long as we win the game."
Chelsea did not appear to miss Costa too much against Leicester, but the Spain international has netted 14 Premier League goals this season and been a key figure in their title bid.
The Blues are next in action on January 22 when they welcome Hull City to Stamford Bridge, with plenty of focus likely to be placed on the team sheet for that fixture.