The 25-year-old has one previous cap for the Three Lions and after his two goals helped the Welsh side to a shock win, his manager claimed he could earn a recall
The 25-year-old’s two powerful headers from corners fired the Bluebirds to a shock 3-2 win over Manuel Pellegrini's men - their first triumph in the top flight for 51 years.
And Mackay believes Campbell, who earned one England cap while at Sunderland in 2012 before form and injuries disrupted his progress, is good enough to force his way back into the international reckoning.
"I think he has got a lot of ability," he told reporters.
"I think he showed today, against top, top defenders, that if he keeps his head down, keeps working hard and keeps playing like that there is a chance that eventually he will be considered for England again.
"I think he’s worth multi-millions. I thought we got him for a fantastic price. He was coming to the end of a contract and it was one of those situations where we were in the right place at the right time for the player."