Celtic have been hard at work in this summer’s transfer market with a flurry of new signings and some major outgoings. The Hoops last week confirmed the departure of Matt O’Riley for £30m to Brighton & Hove Albion, setting a new Scottish record for the highest transfer fee ever received from a single deal. With Celtic agreeing personal terms to sign Arne Engels, Brendan Rodgers is already at work trying to bring in the last few pieces ahead of what is going to be a big season for the Glasgow giants. And the Celtic Park side have now made their move to sign a former Premier League player. Celti…