But Celtic manager Martin O’Neill was attracted to his “experience of high-level football”.
“He has also been involved in European competition, so we are bringing in a talented, experienced, international forward to really enhance our attacking options,” he told Celtic’s website.
Adamu is eyeing a league and Scottish Cup double while scoring “a lot of goals” and wants “to improve as a player”.
Asked what kind of player Celtic fans will see in action, he added: “I’m dangerous in the box and hungry for goals. That’s what the manager sees in me and I want to show that on the pitch.”
The announcement of 22-year-old Mvuka’s signing came eight minutes after the closure of the January transfer window.
However, the Norwegian is no stranger to the Scottish champions, having played against them in the Conference League in 2022 for Bodo/Glimt, where he was a team-mate of Celtic winger Sebastian Tounekti.
He joined Lorient in 2023 but has made only five starts and 10 substitute appearances for the side sitting ninth in Ligue 1.
“Joel is a talented player who has a very good level of experience achieved at some really good clubs,” O’Neill said.
“He will give the squad another option, he is very quick, able to play on both wings”
The 20-year-old Arthur has made just three appearances for Premier League outfit Brentford, including two starts in his season’s League Cup.
However, O’Neill thinks the England youth international is “an excellent player, with real attributes, good height, strength and speed”.
His arrival allows Stephen Welsh to return to Motherwell on loan after being recalled as cover during January.
Meanwhile, Kenny heads for the side sitting third in League One having failed to become a first pick since O’Neill’s return to Celtic.
The 22-year-old Irishman, signed in January 2024 from Shamrock Rovers, has played 22 times for Celtic this season, 12 of them starts, and scoring six times.