Watford are aiming to strengthen in January with their form recently tailing off.
And Express Sport understands the Hornets are keen to sign Manchester United and Arsenal outcasts Shaw and Walcott.
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.
United are keen to sign a new left-back this January amid concerns over Shaw.
Tottenham’s Danny Rose is their standout target, with Jose Mourinho determined to sign the player up.
However, Watford want to sign the former Southampton star as well, with Silva an admirer.
The Hornets feel more is required for them to build on a positive start to life under Silva.
And they are also keeping an eye on Arsenal’s Walcott.
The England international has struggled this season, with Arsene Wenger regularly overlooking him.
Yet Watford, though interested, have their doubts.
Silva is understood to be concerned by the player’s attitude and whether he has the drive to succeed at Vicarage Road.