The football club can confirm the deal for Middlesbrough defender Christian Burgess has been made permanent.
Peterborough United have completed the signing of Middlesbrough defender Christian Burgess for an undisclosed fee on a four-year contract.
Burgess initially signed on-loan and made his debut as a substitute in the 2-1 defeat to Sheffield United at London Road on Tuesday evening.
Ferguson said: 'I am pleased to sign Christian. It is a good piece of business from the football club. He is player that has been on the radar for a little while and he will bring competition to the centre back positions and with Gabi and Jack injured, it is a good time to bring him in.
'I felt he did well when he came on in difficult circumstances on Tuesday evening and he will benefit with a few days training with his new team-mates,' Ferguson said.
Burgess will speak to the media later on Thursday ahead of Saturday's trip to Bradford City.
Burgess will wear the number 21 shirt.