Rangers have completed the signing of Romania international Ianis Hagi on loan from Belgian champions Genk.
The Ibrox club say they have an "exclusive option" to buy the 21-year-old midfielder at the end of the season.
With Jermain Defoe suffering a calf injury, Rangers have also been linked with moves for Hibernian forward Florian Kamberi and Livingston striker Lyndon Dykes.
There could be more outgoings from Ibrox, with Middlesbrough the latest club to be linked to a move for winger Jordan Jones.
Celtic manager Neil Lennon is relaxed about his deadline-day business, refusing to rush into any "panic" buys despite losing winger Mikey Johnston to suspected knee ligament damage.
Aberdeen are looking to add and could offload James Wilson after the forward was linked with a switch to Salford City. Zak Vyner's loan from Bristol City has been terminated after the defender suffered a shoulder injury. Vyner made 18 appearances for the Dons.
Motherwell rejected a bid from Hull for James Scott on Thursday night, with the fee believed to be about £750,000.
Kilmarnock right-back Stephen O'Donnell has turned down the opportunity to move on after Oxford made a reported £200,000 bid.
Manager Alex Dyer said: "There was an enquiry for him but I spoke to him and he wants to stay at the club."
Hearts manager Daniel Stendel is pushing for more signings, with Schalke midfielder Marcel Langer among his priorities.
St Johnstone manager Tommy Wright hopes to make two loan signings after releasing defender Madis Vihmann. The Perth side have been linked with Bournemouth midfielder Matt Butcher.
St Mirren could do more business after re-signing Lee Hodson, with full-back Paul McGinn expected to join Hibs after the Leith club had a bid accepted.
Hamilton loaned Owain Fon Williams to Dunfermline and ended Adrian Beck's loan spell on Thursday and could be active after being hit by several injuries.
Livingston are looking for reinforcements after loaning Scott Tiffoney to Ayr, while Ross County are monitoring the market.
