Jonathan Grounds has ended his loan spell at Hibernian and returned to Middlesbrough.
The left-back was due to have remained at Easter Road until 29 January but he has returned to Teesside after Hibs manager Colin Calderwood failed to agree an extension with Boro manager Tony Mowbray.
The 22-year-old made 15 starts, scoring one goal, after joining the Clydesdale Bank Premier League club in August.
Meanwhile, 18-year-old Hibernian midfielder Lewis Horner has agreed a new contract as he bids to break into the first team.
Aberdeen manager Craig Brown is hoping to recruit at least one midfielder by the end of the week as he bids to continue the club's positive transformation in fortunes.
Brown has targeted Blackburn striker Nick Blackman on a loan deal, after bringing the player to Motherwell in the first half of the season and, with Yoann Folly out for the rest of the season with a broken ankle, Brown admits strengthening the midfield is top of his list.
He told RedTV: "The midfield is critical. It's been well-publicised that we are trying to get a striker, Nick Blackman, on loan and we are very optimistic about that. A bigger priority right now is the midfield. We hope, before the end of the week, to make a signing of a midfield player plus a loan as well. Ideally, we would like two new midfield players.
"The minimum requirements with the fixture list coming up is for us to have two midfield players and another forward player. Then maybe even another defender. We really don't want anyone to leave but we might have to say to one or more of the players, if their agent can get them a club in this window, it's fair to allow them to go."
Hearts will look to put their fourth-round cup exit to St Johnstone behind them against Dundee United at Tannadice on Saturday but it is likely they will have to do without Kevin Kyle and Rudi Skacel. Kyle trudged off during the 1-0 loss to Saints with a groin problem, while Skacel was not risked for the game due to a small calf tear.