Former Arsenal defender Martin Keown has hailed West Ham United's capture of Alex Song.

Keown wrote in the Daily Mail: "Signing Song on loan was one of the most astute transfers of the summer. Plenty of Arsenal fans will be looking at him and asking: 'Why isn't he doing that job in our midfield?' They have a point. Sam Allardyce saw a good opportunity and grabbed it.

"After my final season at Arsenal I was invited back by the club to act as a mentor and was there when Song arrived. He was only 17 but he went straight into training with the first-team group. Along with Abou Diaby, he was earmarked as a potential successor to Patrick Vieira.

"Song's talent was obvious but he still needed a lot of work and Arsene Wenger is one of the best at developing young players."