Stephens eases the pressure on Pellegrino

It is becoming an FA Cup tradition for Southampton's supporters to boo Mauricio Pellegrino's substitutions. Three weeks after they jeered a defensive late change by their manager in the win over Fulham, a minority voiced their disapproval again when Pellegrino made the conservative decision to replace Sofiane Boufal with Maya Yoshida midway through the second half of this forgettable contest.

However, this was an afternoon when the mutiny felt misplaced.

Southampton were narrow but deserving winners, securing their place in the fifth round thanks to a solitary goal from Jack Stephens, and instead it was Watford who looked like the team with bigger problems. Javi Gracia will hope that this is not a sign of things to come. Watford, flattered by a slender scoreline, were wretched. This was presumably not what they had in mind when they sacked Marco Silva last weekend.

There have been times in the past couple of months when Pellegrino has looked like a man on the brink of being thanked for his efforts before being ushered to the exit by his bosses. Southampton have backed him by breaking their transfer record to sign Guido Carrillo for £19.2m from Monaco. Carrillo was named on the bench - the Argentinian made his debut after replacing Dusan Tadic in the 83rd minute - and he must have been impressed with the way his team-mates refused to allow Watford time to adjust to their new manager's demands.

Southampton were full of purpose during the opening exchanges. Boufal's free-kick from the left found the Watford defence in disarray and although Shane Long's effort was saved by Orestis Karnezis, Stephens celebrated his 24th birthday by smashing the rebound home.

Gracia watched from his technical area as his new players frequently conceded possession with aimless passes that suggested they were struggling to focus after an uncertain period.

Southampton were out for revenge after Abdoulaye Doucouré's last-minute handball goal denied them a precious league win over Watford two weeks ago and they almost doubled their lead when Cédric Soares flashed a low centre across the goal after dainty trickery from Tadic.

Long lacked conviction when he burst through on goal and Pierre-Emile Hojbjerg smashed a shot against the bar from 25 yards.

After the break, Watford's changes failed to make an impact. Gracia has his work cut out.

Observer