#4 Andy Carroll
Liverpool signed Luis Suarez and Andy Carroll for world-record fees in December 2011 to replace the departed Fernando Torres. Boy did they have contrasting futures ahead of them! Believe it or not, Carroll was the costlier one, and by a substantial £12 million.
Carroll was a force at Newcastle United, and his goals had led his side to promotion. In his first season in the Premier League, he netted 11 goals in 19 appearances till the January window. Convinced, Liverpool signed him to replace Torres.
He scored only twice for Liverpool that season. The following season he played regularly but managed only four league goals. Suarez was becoming the world-class player he is now, and Carroll was a surplus to Liverpool.
He was loaned out to West Ham and the deal was made permanent in 2013. Injuries and inconsistency have meant that Carroll has made more than 20 appearances only twice as a Hammer. This time he has suffered an injury even before the season commences. That's Andy Carroll for you. After he left Liverpool, anyway.