Reading boss Veljko Paunovic said his side's 1-0 FA Cup third round defeat at Luton was a 'painful' one.
The Royals chief made a host of changes to his team, giving three debuts and selecting 13 players in his squad who have come through the Royals academy.
On his emotions, Paunovic said: "Pride, because of a fantastic performance, especially in the second half, from the whole group and the youngsters. They showed an amazing performance, an amazing spirit in this test.
"But I am also a little bit frustrated as we played very good football, we deserved to score a goal.
"I'm a little bit disappointed too but the most important thing is we saw that we have very good potential in our academy.
"We see the team is on the same page, even without a lot of the players who are usually starting, so you saw our identity. I'm very happy, and if you have to lose, it's better to lose it this way.
"I'm very disappointed after the game in the changing room to see all those guys giving so much and not getting a result,
"it was a little bit even painful for me but that also tells you that they are winners, they are not complacent, and that's a very good policy."
After a quiet opening to the game, Moncur broke the deadlock in magnificent style on the half hour, volleying James Bree's high cross into the net for his third goal of the season.
Luton's Croatian international then made a superb double stop from Sam Baldock and Jayden Onen, before the visitors should have levelled in stoppage time when substitute Nahum Melvin-Lambert hit the bar and Onen volleyed over.
Hatters boss Nathan Jones added: "In the first half he (Sluga) didn't have much to do.
"I thought we were excellent in the first half, but then we kind of made it hard for ourselves. We didn't come out of the blocks flying, which is what we wanted to do.
"We gave the ball away too easily and allowed them to break on us and gain the momentum and it was difficult to get it back.
"He (Sluga) has made some good saves, a lot of them were from distance and some they've missed.
"It's good to get in the hat but we could have made it a lot, lot easier for ourselves."