Billy Barr admitted his side were far from their best as they squeezed past ten-man Arsenal to reach the fourth round of the FA Youth Cup.
A second half strike from Daniel Butterworth settled the tie between last season's beaten semi-finalists in Rovers' favour.
In a close and competitive contest at Boreham Wood, the hosts had to play more three-quarters of the game with ten men after Gunners forward Reiss Nelson was sent off midway through the first half, but Rovers struggled to make the most of the man advantage until 12 minutes from time.
"I didn't enjoy that one bit," said Barr after the match.
"We've been unfortunate this year to have gone down to ten men on a couple of occasions and we know how hard we make it for the opposition, and we've come out of games with a point when we've had ten men.
"With the 11 it is different, you've just got to be patient and we felt it was coming, it is a great ball in from Lewis Thompson and a great finish from Dan Butterworth.
"But we have to learn to be braver with the football and really try and open the opposition up.
"Obviously the defining moment in the sending off but they are still a very good team. If you let them have the ball they'll cause you problems and I think we let them have the ball too often tonight and they opened us up, where I was hoping it would be us doing it to them.
"It was better in the second half, but it can be a lot better again. We'll have to learn from it and make sure we are better."
The result means Rovers will now face a home tie against Aston Villa in the next round, a side that Barr's men knocked out on their way to the semi-finals last season.
"I went down to watch Aston Villa play Arsenal, primarily to see Arsenal, but they drew n the day and Arsenal scored very late on," added the Under-18s coach. "They played a different way than what they did last year but we know it is going to be a really difficult game again.
"This time we are at home so we are going to have to be a little more positive and try and get on the ball more."
The date for the fourth round tie will be confirmed in due course.