Celtic manager Neil Lennon has confirmed he will continue to look at trialists Rabiu Ibrahim and Ingolfur Sigurdsson.
The Hoops boss is trying to strengthen his squad this month and has been running the rule over 20-year-old Nigerian midfielder Ibrahim.
Icelandic winger Sigurdsson, 18, has also been training with the club this week and Lennon has announced he will extend the pair's trial period.
"We are just having a look and they will be here for another couple of days," he said.
"But we have been impressed by both of them."
Lennon also stressed that he does not expect Mexican midfielder Efrain Juarez back at the club this month, despite reports he is set to end his time at Real Zaragoza.
"I am not aware of that," he said. "He is on a year-long loan so I would expect Zaragoza to adhere to that, unless we are told differently.
"I know there has been a change of coach there but I have no contact from Juarez or his agent, so it's as you were, really."
And responding to such queries is one of the reasons why the Celtic chief is "bored" with the concept of a winter transfer window.
"I don't like it," he added. "I think we should go back to having an open market throughout the season.
"You have to do all your business in a short period of time and it is very difficult to do that at times.
"I get bored with it. I get bored answering the same repetitive questions, speculating on players coming in and going out and I can only reiterate that I don't want to sell any of my players, and if I can add one or two to my squad then I will try and do that.
"January is a difficult time, clubs want to hold on to their better players and negotiations can be difficult.
"But we are still looking. If there is a player who can make us better we will look at it."