When does he have to be added to the 40 man roster? I think he gets another year? If he had to be added, then I'd definitely see him come up at the end of the year. If not, then I could see him just finishing out the year at Rochester and being invited to next year's spring training.
Give Kieboom or an FA a run at 3rd, then if Alu does well in Rochester and Kieboom Kiebusts, swap them at some point in 2023.