Martin O’Neill has confirmed Celtic are trying to sign another left-back to provide cover for Kieran Tierney. The Scotland international was one of Celtic’s best players, but O’Neill knows he cannot be expected to play every game across the season. Asked if Celtic needed to bring in cover at left-back, he said: “Of course, of course, and that’s something we are definitely looking at. O’Neill also said Celtic have young players coming through the academy, but made clear it is too soon to rely on them as Tierney’s main back-up. That leaves left-back as one of the clearest areas Celtic still need to strengthen before the transfer window closes.