Glasgow Rangers signed Ryan Jack from Aberdeen, and a former Ibrox full-back has backed him for success.
Mark Warburton's men take on former Rangers defender Foster when they face St Johnstone at Ibrox tonight.
St Johnstone defender Richard Foster comments on Glasgow Rangers manager Mark Warburton.
Richard Foster was one of the Rangers players to be criticised by Dave King.
Rangers released Richard Foster following their play-off defeat to Motherwell.
Rangers have started their summer rebuild by releasing 11 players.
Motherwell came away from Ibrox with a commanding lead after beating Rangers 3-1.
Richard Foster is looking for Rangers to take advantage of Motherwell's poor away record on Thursday night.
The Rangers defender claims that the play-offs are in favour of the Premiership teams.
Rangers defeated Hibernian 2-0 at home in the Scottish Premiership playoffs on Wednesday evening.