The player gets a move to the German top-flight, Bayer Leverkusen get a promising talent to develop and the Parkhead turn around a significant profit on a defender they recruited from Manchester City.
It does, however, leave Celtic light in the position. Kristoffer Ajer has been playing well in the role and provided a bit more defensive stability with Frimpong’s levels having dropped. Behind the Norwegian there is not a lot of depth with Anthony Ralston on the bench against Hamilton Accies on Wednesday night.
Another aspect of the departure of Frimpong is that it makes it difficult for Neil Lennon to play with wing-backs, even more so with James Forrest still out injured.
The Celtic boss revealed that even with the £11million it could be difficult due to the impact of the pandemic on finances but he did admit that he was looking to bring one or two in.
One consideration for new signings is whether Lennon will still be Celtic boss in the summer when many expect an overhaul. There is every chance signings this month could be loan deals or free agents.
We will look at some possible options for Celtic, all with British football experience, many of which would likely be cost-effective and more than capable short-term fixes.
Scroll down and click through to see the seven players chosen from the UK and around Europe.
5. Ezequiel Schelotto
A free agent, the Argentinian-born former Italian international hasn’t played since June. However, would bring experience to the Celtic defence having played in the English, Italian and Portuguese top flights. Photo: Bryn Lennon
6. Eric Lichaj
Out of contract after leaving Turkish side Fatih Karagümrük earlier this month. He was a regular in the Turkish top flight before succumbing to an injury which could put Celtic off. But has plenty experience of British football with more than 300 appearances for the likes of Nottingham Forest, Hull City, Aston Villa and Leeds United. Photo: Shaun Botterill
7. Neco Williams
The teenager has clearly impressed Jurgen Klopp making 11 appearances in all competitions for Liverpool. There is clearly talent there and naturally has been labelled the ‘next Trent Alexander-Arnold and he has the ability to cover the whole flank. Has received some social media criticism for a couple of performances. Regular game time at Celtic could be a great step in his development. Photo: Gareth Copley