Liverpool have bolstered their backline with the signing of Preston defender Ben Davies, the PA news agency understands.
The Reds have been so short of fit centre-backs that captain Jordan Henderson has been deployed there in recent weeks but Davies has emerged as a surprise choice to reinforce their ranks.
It is understood the 25-year-old was undergoing a medical on Monday before signing for an initial £500,000.
Preston will also benefit from a 20 per cent sell-on clause on any profit Liverpool make on any further transfer with a further payment if Davies plays for England, while North End will get 19-year-old Liverpool defender Sepp Van Den Berg on loan.
Liverpool were also interested in bringing in Marseille's Duje Caleta-Car but that became problematic so they have now switched their attention to a loan deal for Schalke's Ozan Kabak.
Yokuslu's arrival follows those of Mbaye Diagne, who moved on loan from Galatasaray, and Robert Snodgrass, while the Baggies have also agreed to take England international Maitland-Niles on loan for the rest of the season.
Southampton were interested in Maitland-Niles but PA understands they pulled out because the player did not appear sold on the switch and are now eyeing up a move for Tottenham's Japhet Tanganga.
Bournemouth are interested in Shane Long but Saints would only let the striker leave if they can get in a replacement like the Cherries' Josh King, which looks unlikely at the moment.
There will be no incomings to boost Manchester United's Premier League title bid but teenager Teden Mengi will spend the rest of the season playing under Wayne Rooney at Derby.
PA understands Chelsea have chosen not to send Billy Gilmour out on loan. New Blues manager Thomas Tuchel wants the teen star to stay at Stamford Bridge.
Crystal Palace manager Roy Hodgson, meanwhile, poured cold water on talk Patrick Van Aanholt and Christian Benteke could leave the club.
Glenn Murray is looking forward to working with former Brighton boss Chris Hughton again after he completed a permanent move to Nottingham Forest.
The 37-year-old spent the first half of the campaign on loan at Watford, but was recalled by the Seagulls and allowed to bring his long association with the Premier League club to an end.
West Ham defender Winston Reid has joined Brentford on loan until the end of the season.
The 32-year-old New Zealand international spent the first half of the season on loan with MLS side Sporting Kansas City after recovering from a serious knee injury sustained in March 2018.
Galatasaray have completed the signing of United States defender DeAndre Yedlin from Newcastle, who have been linked with a loan move for Leicester's Hamza Choudhury among others.
The success or otherwise of their search for midfield reinforcements could have an impact on Matt Ritchie's proposed return to Bournemouth.
Goalkeeper Jonas Lossl has left Everton to return to Danish side Midtjylland, his first professional club.
The 32-year-old did not make a first-team appearance for Carlo Ancelotti's side following his move from Huddersfield in 2019.
Norwich have completed the signing of former Aston Villa goalkeeper Orjan Nyland on a short-term deal until the end of the season.
Birmingham have completed the permanent signing of teenage forward Keyendrah Simmonds from Manchester City while Blackburn have signed left-back Harry Pickering from Crewe for an undisclosed fee.