Celtic have done some excellent pieces of business since the inception of the January transfer window.
In HITC Sport's first part looking at Celtic's most memorable deals during the January sales, we look at arguably their five best acquisitions since the window's inception more than a decade ago...
5. Tom Rogic
If this list is compiled in a couple of years time, it would not be a surprise to see Tom Rogic much higher than fifth. The Australian has always been capable of making something special happen, but now he is starting to show it on a regular basis under Brendan Rodgers.
4. Robbie Keane
Robbie Keane needed just 16 league games to win the Celtic Fans' Player of the Year award in 2010. He managed to score 12 times in the Scottish Premiership during his loan spell, leaving many Bhoys supporters to wonder what he could have done had he been signed up permanently.
3. Georgios Samaras
The Greek striker enjoys something of cult-hero status amongst Celtic fans following his six year spell at Parkhead. While he was unspectacular during his initial loan spell, he made the most of the opportunity when he was signed permanently and went on to score more than 50 league goals.
2. Kris Commons
Given Kris Commons' contribution to Celtic, it is certainly a surprise that his Hoops career has fizzled out in such a way. At his best, he was simply sensational - he scored 27 league goals during the 2013-14 campaign alone - and he certainly deserves to be a player with five league title medals to his name.
1. Leigh Griffiths
Though he has been somewhat overshadowed by Moussa Dembele this term, there is no question that Leigh Griffiths is the talisman for Celtic. His strike-rate for the Hoops is phenomenal, and worryingly for the rest of the Scottish Premiership, his best years should perhaps still be ahead of him.