Celtic are searching for potential additions and supporters are curious about who Brendan Rodgers could add to his squad. In among links with reported targets such as Martin Dubravka and Peter Vindahl Jensen, there has been chatter in Hoops circles involving one or two former players who may be available this window, even if merely speculative. The mind wanders once the market is open due to excitement, and in line with more or less every window, the subject of Kieran Tierney’s future at Arsenal has been circulated following suggestions that he could be free to leave North London for a fee of …