Rooney powerfully headed home Aberdeen's second goal in a 4-0 procession against Kilmarnock at Rugby Park in his 91st game for the club.
The triumph allowed Aberdeen to move one point behind Ladbrokes Premiership leaders Celtic following Motherwell's shock win at Parkhead.
Rooney has reached his half-century less than two years after moving up from Oldham, initially on loan.
And McInnes said: "Any player you sign you always hope it works out but Adam in my team, with the players round about him, was always one we were really confident it would work.
"But he deserves a lot of credit because he gives a performance every time and is selfless with his work. He gets battered about by centre-halves but fights his corner for the team.
"We know when we can get the right service, as we did today, he will put things away.
"He has scored a lot of important goals for us, winning goals, a winning cup final goal with the penalty kick. He has been excellent and long may it continue."
Source: Eurosport