After running out comfortable winners against Bury in their previous Premier League Cup fixture, Wolves found themselves 4-0 down before half-time on the South Coast, with AFC Bournemouth fielding several first-team players in their side.
Sellars says his young side will learn a lot from the experience and has called on his players to bounce back.
"I think the last game against Bournemouth was a massive learning curve," he said.
"But, as a footballer, you're going to have bad performances, you're going to have bad halves - they're human beings, not robots.
"The second-half gave them the opportunity to show what they’d learnt.
"I thought they recognised the importance of hard work, making sure that you're working clever in your organisation and your structure, and making yourself difficult to play against.
"If we do that, then that allows your creative players to be creative. We have to get back to what we’re good at.
"Sometimes in football, you can’t always play well, but if you work together and work hard you can pick up results."
The Under-23s have been in solid form in recent months, with just one defeat their last 11 outings before Monday’s result, and Sellars is focused on getting back to winning ways when they play Middlesbrough on Monday.
"The run was really good but that’s football. What we’ve got to focus on is getting back to good and consistent performances over the 90 minutes and hopefully the results will come.
"I’ve been really pleased with them overall, some of the football we’re playing has been really good.
"I haven’t lost confidence or belief in them, I think it’s just about getting back to some hard work.
"The great thing about football is that it's not like boxing where you've got to wait six months for your next fight, another one comes quickly.
"Monday is a good opportunity for the lads to prove that the Bournemouth game has gone and we’ve learned from it."
