Ward-Prowse struck in defeat at Manchester City on Saturday.
Speaking to the Southampton FC website, Ward-Prowse said: “You can't question the lads' commitment.
“Obviously, I'm with the team every day and I know them very, very well – not only as footballers but as people.
“We came here on Tuesday and we came here on Saturday, and we've made stepping stones, so for people to question our commitment, you could see that's definitely not the case.
“That's the most important thing for us – for us to come off the pitch, regardless of the result and performance, to show the character and belief in what we're trying to do.
“You could see that right through the game, and also the quality we've got going forward at times. All in all, it was a positive performance."