Scottish giants Celtic signed Swedish international defender Mikael Lustig from Norwegian side Rosenborg. The 24-year-old, who has been capped 23 times, will join Celtic in January after signing a three-and-a-half year contract. \"This is a really exciting time for me and I am delighted to be committing my future to Celtic,\" Lustig told the club website. \"I know a lot about Celtic, about the size of the club.\" Lustig agreed to join them despite the club already having three right-backs in the squad. \"I\'m really looking forward to joining this squad, to the challenges ahead and hopefully playing my part in bringing some success to the club,\" he said. Celtic manager Neil Lennon said Lustig was a class signing who also brought much needed versatility as he can also play in central defence. \"We are delighted to bring Mikael to Celtic,\" Lennon said. \"We believe he has the qualities to make a real impact at the club and we look forward to him joining us in January. He is a player with international pedigree and a defender with great versatility. \"He is someone who I feel will be a very positive addition to the squad. I like his attributes and he can play both positions, but he\'s predominantly a right-back.\" Celtic have had a disappointing season thus far and trail bitter rivals Rangers by ten points in the Premier League title race, though, they have a game in hand.