Everton have contacted Celtic over the availability of Canada international right-back Alistair Johnston, according to the Scottish Premiership club’s manager, Martin O’Neill.The departure of long-term captain and stalwart Seamus Coleman, plus uncertainty over the future of Scotland’s Nathan Patterson, means the Merseyside club are looking to sign a new right-back this summer. They have considered a number of options, including Strasbourg’s Guela Doue, but the search has now led to them approaching Celtic over Johnston, 27.In a press conference ahead of the Scottish champions’ league opener against Dundee on Monday, O’Neill confirmed Everton manager David Moyes had been in touch “last week” over a potential move for the Canadian.Sources with knowledge of the situation, speaking on condition of anonymity to protect relationships, insist a firm bid is yet to materialise, with Everton still assessing other options in the right-back position.“Everton have been in contact and I’m not sure whether there’s been a bid in there for that one, but they’ve been in contact saying that they would be,” O’Neill said in a press conference ahead of Celtic’s Scottish Premiership opener against Dundee on Monday.“In fairness, David did call me last week and saying that there would be contact. But I don’t know how far that has progressed, if it has at all.