Rangers have pulled off a deadline-day coup by signing Wales midfielder Aaron Ramsey on loan from Juventus.
The out-of-favour Juve player opted for a switch to the Scottish champions despite interest from the Premier League and elsewhere.
The 31-year-old, whose contract in Turin runs until the summer of 2023, is one of the biggest signings to hit Scottish football in recent seasons.
Meanwhile, St Mirren have had fresh approaches for Republic of Ireland midfielder Jamie McGrath.
Manager Jim Goodwin said: "This afternoon there are conversations ongoing between our club and a couple of other clubs but as with anything there is a cost involved and it is up to the buyers to meet the valuation that we put on the player."
Rangers earlier announced the signing of 20-year-old right-back Mateusz Zukowski from Lechia Gdanks but failed with an improved bid for John Souttar, which was understood to be in the region of £400,000.
Hearts were assessing potential options in case Souttar left late in the day but were otherwise happy with their business.
Celtic had their new arrivals sorted before deadline day but there have been loan departures from Parkhead.
Former Sheffield Wednesday defender Osaze Urhoghide has joined Oostende with the Belgian side holding an option to buy, while 19-year-old Adam Montgomery has joined Aberdeen.
St Mirren signed former Kilmarnock and Rangers winger Jordan Jones on loan from Wigan until the end of the season after allowing Kyle McAllister to join Partick Thistle in a similar deal.
Dundee have confirmed the signing of Zak Rudden after agreeing a loan swap deal that sees Alex Jakubiak move to Partick Thistle on loan for the remainder of the season.
Dundee also tried to speed up the arrival of another pre-contract signing but Motherwell rejected their bid centre-back Ricki Lamie.
"It's nowhere near our valuation so that’s in Dundee’s court now as to whether they come back," said Well assistant manager Chris Lucketti, who did not expect any late signings at Fir Park.
Hibernian were working to bring in a replacement for Martin Boyle and could bring in Brandon Barker after the deadline after the winger left Rangers by mutual consent. They have signed 20-year-old Norwegian winger Runar Hauge but he will start off in the development squad.
Players could leave Easter Road but manager Shaun Maloney insisted Drey Wright would not be one of them after he was linked with a return to St Johnstone.
"Scott Allan could possibly leave," Maloney added. "I’ve been really clear with Scott. At the moment it’s a 'no’. I see him with us tomorrow but if that changes and it’s something Scott really wants, I will support him in getting something that suits him.
"Alex Gogic really wants to play more minutes and if he finds a solution I’ll be happy to help him with that."
Dundee United confirmed the loan signing of 20-year-old defensive midfielder Tim Akinola from Arsenal and sold forward Louis Appere to Northampton for an undisclosed fee.
Aberdeen were trying to make other signings other than Montgomery and manager Stephen Glass expected Calvin Ramsay and Lewis Ferguson to be in his plans for the game against Ross County on Tuesday.
St Johnstone signed 22-year-old striker Theo Bair from Vancouver Whitecaps for an undisclosed fee and secured a loan deal for Cardiff’s Tom Sang, who can play in defence or midfield.
Ross County boss Malky Mackay has one long-term deal almost tied up, which could be announced later in the week, and was pushing for a second signing.
"There should be one that comes in on a two-and-a-half year contract and I’m hopeful to get a loan done," he said.
Livingston manager David Martindale was not anticipating much activity, if anything.
"We have been a wee bit active ourselves trying to get a couple of bits and bobs but nothing significant," he said. "I got most of my stuff boxed off early."