Celtic manager Neil Lennon wants to bring in two new faces before the transfer window closes.
With midfielder Ki Sung-Yueng on the verge of completing a
£6m move to Swansea,
Lennon is keen to bolster the Scottish champions' squad.
However, the Northern Irishman said recruits were unlikely to arrive before next Wednesday's Champions League qualifier against Helsingborgs.
Midfielders Joe Ledley and Beram Kayal face a period on the sidelines.
Lennon said: "Joe has a grade-one groin injury and he will be out for a couple of weeks. Beram has had a reaction to his other ankle and he will be maybe three to four weeks.
"The injuries aren't majorly concerning, particularly Joe's injury.
"Joe has been one of the best signings since I came to the club, and so consistent. He is a big loss to us.
"Beram is a little bit of a worry because it is his other ankle which is giving him bother.
"It is unfortunate, but the midfield is probably the strongest department at the club.
"We have Victor Wanyama to come into the squad and we have options."
Lennon was keeping tight-lipped on his transfer targets but did admit he admires Japanese forward Yuki Otsu, who
impressed during the Olympic Games.
Yuki Otsu scores for Japan against Spain during the Olympics
The 22-year-old is with German club Borussia Monchengladbach, although the Celtic boss was cool on an imminent move.
"He's a player that we like but we'll probably not do anything this window," he said.
"We'll just keep tabs on him for now."
Celtic are in a very strong position to reach the lucrative group phase of the Champions League, having
beaten Helsingborgs 2-0 in the first leg
of their play-off in Sweden.
However, Lennon stressed that the club will remain prudent in their spending.
"If we do qualify, we won't be spending £6m or £7m or anything like that, it will be sensible," he said.
"We have a structure in place, regardless of whether we go through or not, so it will be players within that bracket that we think will enhance us.
"Obviously, we'll have a better chance of attracting better players if we get through to the Champions League.
"We've been working away in the background for three or four players.
"Whether we get over the line with those, I don't know, but I can't see us bringing anybody in before Wednesday."