Vidal, 19, became signed on Friday from City on a loan deal until the end of the season.
Vidal knew Aberdeen's Aluko from having played together in the England youth set-up at under-17 and under-18 level.
Calderwood said: "Sone knows Javan really well from the England set-up and he only had good words to say about him.
"Manchester City have a wonderful youth set-up and Sandy Clark has seen him play with them and gave him a lot of good reports.
"I hadn't seen Javan before we signed him but he's quick and he's comfortable on the ball. He was within our budget so it was pleasing to get the deal done in the end."