Luke McCowan will be catching his breath after a busy few days that culminated in him moving to Celtic and featuring in his first Glasgow Derby. The 26-year-old joined the Bhoys for £1 million on deadline day despite Hibernian’s willingness to push his arrival through the door. However, he only wanted Celtic. Speaking after coming off the bench against Rangers last weekend, the former Dundee captain admitted his debut was the ‘stuff of dreams’ as a boyhood supporter of the club. He stated post-match: “The stuff of dreams, really; if you could tell me as a kid that I’m going to come on in a gam…