SAINTS interim boss Simon Rusk insisted 3-0 defeat to Aston Villa was "quite harsh" after he was left encouraged despite moments of "naivety".

Ollie Watkins climbed off the bench to help fire Aston Villa to victory and keep Saints searching for points to surpass Derby County's record.

Villa were labouring against the already-relegated Saints until Watkins struck, just four minutes after Aaron Ramsdale saved a penalty.

Fellow substitutes Donyell Malen and John McGinn put the match beyond Saints, with the third goal coming after Ramsdale saved a second spot-kick.

Speaking after the match, interim Rusk said: "I thought there was a lot of grit to our performance in the first 70 minutes of the game.

"The first goal comes after 73 minutes against a top, top, top team. We knew there were going to be moments where we had to suffer without the ball.

"That was part of the plan, and I think we can be pleased with lots of the blocks, the passion around the defending and the ability to deal with set pieces.

"We're really disappointed with conceding quick goals, but we have to respect a Champions League quarter-finals team coming here.

"But we're really disappointed with the outcome, the players gave everything, and we have to use what was good about it and improve the other bits.

"I think most people would have said if we're 0-0 on 72 minutes, it's gone okay. In the end, all things considered, I think 3-0 was quite harsh."

Rusk believes sacrificing attacking players for a more defensive approach was the correct method to attack the game, citing its early success.

"We've seen this year that in this division, if you open up in another way, 45 minutes you can be out of the game," he explained.

"The plan here was to be intelligent about what we're doing, to be diligent. We want to control parts of the game, and we want to be a threat.

"But I think we can be encouraged by what we saw. You're always going to have to ride your luck against these top teams."

Saints conceded the first goal after an Aston Villa counter-attack and a decision that left their players furiously surrounding the official on the field.

They felt referee Thomas Bramall should have halted play for a foul on Mateus Fernandes before Tyler Dibling conceded possession on the attack. 

"I've not actually watched it back or seen it back yet, so I don't want to be too strong with my opinion on that," admitted Rusk.

"But my feeling at the time was, I think there was a similar incident in the first half where the referee might have stopped it.

"Maybe it's a bit of a moment of naivety, confusion, I'm not quite sure. I haven't quite got the bottom of it but yes, I think it's disappointing."