Celtic boss Neil Lennon has refused to name his transfer targets but confirmed he is looking to bring players to the club in January.
Lennon has watched Huddersfield twice in the past week, against Burnley and Bolton, and speculation is mounting that Celtic are hoping to sign striker James Vaughan.
Vaughan has scored 12 goals so far this season for the Championship club, and Lennon revealed he rates the player.
"I've been watching a lot of players," said Lennon, whose team face Motherwell in the Scottish Premiership at Fir Park on Friday night.
"I'm not here to talk about one specific player. There were 22 players at Huddersfield-Burnley and 22 players at Bolton-Huddersfield.
"Maybe I wasn't specifically looking at James Vaughan. I've been linked with him and that's fine, people are putting two and two together.
"I have spoken to Mark Robins, I know Mark from my playing days. So it's not just James Vaughan I'm looking at but he is a player we think is a good player."
Some media outlets in Scotland have insisted Huddersfield manager Robins is reluctant to sell the 25-year-old.