Scoring goals hasn't been a problem for the youngsters this season but they came up short in the third round of the competition on Tuesday evening.
After a goalless first half, both sides struck the woodwork, but it was the home side Cardiff who grabbed the all-important goal, Yora Enzam firing home with 11 minutes to go.
Rovers huffed and puffed in an attempt to force the tie to extra-time but it wasn't to be.
"It is very disappointing," Lowe told Rovers Player
post-match. "I thought we controlled the game for long periods but couldn't produce enough quality close to their goal to make our possession count.
"Then obviously we fell for the sucker punch late on in the game where we didn't defend a cross particularly well and got punished.
"To be fair they'd had a few attempts on our goal as a bit of a warning for us, but generally speaking, close to their goal we just didn't produce enough quality to really get a foothold in the game and go ahead.
"Everyone is really disappointed, the boys, the staff, it is a bit of a letdown really, but that is football. It will test you and test your character.
"We've a couple more games before Christmas and then there's a break and then the back end of the season to look forward to.
"At the end of the day it is about those boys developing, they'll have to deal with the defeat today and come back ready to go against Sunderland away at the weekend."