Millwall have re-signed defender Jake Cooper from Championship rivals Reading for an undisclosed fee.
Cooper featured in 18 games for the Lions last season after joining on loan in January and has now agreed a three-year deal.
The 22-year-old made 54 appearances for Reading, having come through the club's academy system.
"I'm very confident that he can go on to become a top, top centre-half for the club," Lions boss Neil Harris said.
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