Russell Martin’s side were forced to settle for a 1-1 draw at Vicarage Road thanks to a 96th-minute leveller.

They remain unbeaten in 12 Championship matches despite Rhys Healey’s late goal, which cancelled out an opener and first goal since August for Che Adams.

Armstrong wants Saints to turn their regret into three points at Coventry, with the Mark Robins outfit experiencing an upturn in their form.

Speaking to the Daily Echo, Armstrong said: “It’s frustration when you lead for so long and it’s the dying moments when they score, it’s always going to hurt.

“It’s a huge positive to be 12 unbeaten and every point counts in this league so, as much as it hurts, you have got to take the positives.

“For large parts of the game, especially in the second half, I thought we were very good, so we will take the frustration into Wednesday and make sure we win.”

The Scot added: “Watford disrupted us quite well in the first half, they were very compact and we found it hard to break through.

“We adapted at half time and changed a couple of little things so the space began to grow in the second half.

“For teams that press you for a long time, it’s hard to sustain, and naturally gaps appear. I am glad we improved our performance in the second half.”

Martin substituted Argentina youth international Charly Alcaraz at half-time, with Armstrong’s compatriot Ryan Fraser introduced.

The width provided by Fraser led to Adam Armstrong setting up Adams for the first goal. Adams last went on to score three in three matches in August.

Armstrong insisted: “Every striker feeds off goals and confidence, so I am really pleased for him.