Chris Sutton has urged Celtic to make more additions in the last two days of the transfer window, especially up top, where he indicated they compare unfavourably with rivals Rangers.
Celtic raised £25m from selling Kieran Tierney to Arsenal earlier this summer, while they recently scored a financial boost by reaching the group stage of the Europa League.
There have been calls for more signings as worries persist over Rangers putting in a strong title challenge to derail the Bhoys' nine-in-a-row charge.
Celtic snapped up winger Mohamed Elyounoussi from Southampton on Friday night, on a loan deal, but Sutton stressed that they need to do more before the window slams shut on Monday.
He believes Celtic lack strength in depth and feels the problem is especially clear in attack, where Rangers boast Jermain Defoe and Alfredo Morelos.
Sutton said on BT Sport: “They've signed Elyounoussi, which I think is a reasonable piece of business.
“But I still think the big thing for Neil Lennon is the board have to back him and strengthen in the last couple of days.
“They don't have the strength in depth.
“Centre forward, they have one really recognised centre forward; Rangers have two in Defoe and Morelos.
“So that tells you everything.”
Celtic have been linked with a move for CFR Cluj striker Bilel Omrani, while they could also make other additions.
Rangers too could yet make another signing before the window closes on Monday night.
