The sky appears to be the limit for Manchester United midfielder Kobbie Mainoo. Few could have predicted such a meteoric rise for Mainoo even a year ago. The Stockport-born midfielder had shown potential but had made just three appearances heading into this season. Mainoo has completedly exploded this term, making himself almost undroppable in Erik ten Hag’s midfield. The poise, composure and maturity of Mainoo has been simply astonishing to watch this season and the hype is only building. Mainoo came off the bench for his England debut against Brazil on Saturday, earning praise from Gareth So…