Celtic have suffered defensively of late, and Neil Lennon may need to consider some reinforcements in January.
The Bhoys have leaked 17 goals in just five Europa League games, meaning they have crashed out of the group stage.
Summer signing Shane Duffy hasn’t impressed, and there are doubts over Kristoffer Ajer’s long-term future at Parkhead.
On Wednesday night, one former Celtic defender was in action as Erik Sviatchenko started for FC Midtjylland against Liverpool.
Sviatchenko played his part in a 1-1 draw, and even went close to scoring with a powerful header, but Caoimhin Kelleher kept him out.
The Dane fell out of favour at Celtic after a January 2016 move from Midtjylland, but has now rebuilt his career with a return to the Danish side.
Sviatchenko, 29, turned in a strong display last night, and Celtic fans took to Twitter to react to his performance against a strong Liverpool side.
Some feel that Celtic made a big mistake letting Sviatchenko go, with some adding that they miss him.
Others called him ‘solid as a rock’ and urged him to come back to Parkhead, telling Celtic to bring him back to the club.
In other news, Liverpool fans rave about Peter Gulacsi's Euro 2020 display