Sunderland have completed the signing of Celtic right-back Adam Matthews for a fee of £2million.
Diego Poyet is determined to establish himself in Slaven Bilic's West Ham side this season and avoid another loan spell.
Brest have sacked coach Landry Chauvin.
The Brittany club have slipped into the Ligue 1 relegation zone after just one win, and six points, in their last 10 games. They are currently two points adrift of safety with eight games remaining.
A statement on the club's official website this morning read: "Stade Brestois recognise a series of bad results which have put the club's Ligue 1 survival in peril.
"This situation has led Michel Guyot, president of Stade Brestois, after consultation with the principal directors, to separate from coach Landry Chauvin.
"The club's directors will advise very soon on the appointment of a new coach."