Former Liverpool midfielder Jamie Redknapp has expressed his disbelief that Southampton only paid £4million for Charlie Austin.

Austin marked his debut for Ronald Koeman's Southampton by scoring in the Saints' 1-0 win over Manchester United on Saturday and Redknapp believes the Saints have got themselves a bargain by landing the striker at such an affordable price.

"As soon as they announced his signing I couldn't believe they only paid £4million for him," Redknapp wrote in his column for the Daily Mail.

"People talk about his injuries and that he has no ligaments in his knee but he never missed a day's training at QPR.

"With Graziano Pelle without a goal since November, Austin gives Southampton lovely options up front. They had a bit of a blip but now that's three wins in a row with six scored and none conceded. They have kicked on."