Former Rangers midfielder Barry Ferguson believes Celtic defender Christopher Jullien could prove to be a huge signing for the club.

The Frenchman was recruited from Toulouse for £7m in the summer and has been a commanding presence at the back for the Hoops so far this season. Ferguson feels he is now a key part of a defence which is looking more impressive as the weeks go by.

“Well, you seen that in the Old Firm game. I thought the defence was excellent. Bolingoli at left-back was good, Jullien, every time I watch him I think he’s going to be a massive player for Celtic.”

Jullien did take some time to settle at Celtic Park, but he has been in superb form over the past month. He was excellent in the Old Firm derby win, as Ferguson says, and he will be looking to build on his good start in the coming months.

The Frenchman will know Celtic’s next opponents very well. The Scottish champions face Ligue One side Rennes tomorrow evening in the Europa League, and the Hoops’ newly found defensive solidity will be put to the test.