Watford are joining the battle for Manchester United fullback Luke Shaw.

The Daily Express says Watford are aiming to strengthen in January with their form recently tailing off.

Shaw's United future remains uncertain despite the England international recently returning to the fold.

The defender has struggled to earn the trust of Jose Mourinho ever since the 54-year-old replaced Louis van Gaal as Manchester United boss in the summer of 2006.

Newcastle United and Tottenham are both pursuing a deal for Shaw for the January market.

However, Watford want to sign the former Southampton star as well, with Silva an admirer.