What's it all about, Alfie?

Today's Guardian reports that West Ham are preparing to test Swansea City with a £20m bid for defender Alfie Mawson. It's doubtful if Swansea will sell him, having lost Sigurdsson and Llorente, but it might be a good move if WHU can get Mawson. He's quite a handy player who is an England Under-21 international. He scores the odd goal from set pieces, and at 23 is a lot younger than Collins and Fonte. Alfie's also a Londoner and would presumably be quite attracted to a move back to the capital having previously played for Barnsley and Swansea.