Manchester: Manchester United manager Louis van Gaal was forced to defend both his tactics and squad management following a disjointed 0-1 home defeat by Southampton in the Premier League.

Louis van Gaal
Louis van Gaal 

Substitute Dusan Tadic's 69th-minute goal earned Southampton a first victory at Old Trafford since January 1988, which allowed Ronald Koeman's side to climb above United to third place in the table. United misfired badly in attack, failing to muster a shot on target in a home league game for the first time since May 2009.

Sunday's defeat left them with 37 points from 21 games — the same amount as Van Gaal' hapless predecessor David Moyes had mustered at this stage last season.

On being asked if United had struggled to bring the ball out of defence, Van Gaal replied: "I don't think so, because we were the dominating team. You have seen that today (Sunday). That for me is not any question."

Van Gaal also had to explain his decision to omit Radamel Falcao from his 18-man squad, having selected 19-year-old striker James Wilson ahead of the Colombia international.

With Luke Shaw, Daley Blind and Angel di Maria playing after injury, Van Gaal said he needed defensive and midfield cover on the bench and had plumped for Wilson over Falcao "because I know I want speed in attack".

In the end, Van Gaal threw Marouane Fellaini on as an auxiliary striker, but Juan Mata squandered late chances to equalise when he failed to convert a pair of excellent opportunities created by Blind.