Runaway Premier League leaders Liverpool looked to be heading into the fifth round for the first time since 2015 after a fine first-half finish by 18-year-old Curtis Jones was followed by Donald Love's own goal in the opening minute of the second half.
Ricketts said, "They were excellent, they really were. I told the players at half time that the game was there for them.
"The belief within the group is unbelievable, for a new group they have a never say die attitude.
"Jason [Cummings] came on and he's a goalscorer. I was waiting and waiting to put him on then I finally did and he gets the chances and takes them."
"If we'd won it definitely would have been the biggest moment of my career. The game was there for us but I couldn't ask for any more, they've taken a team that's very, very good all the way.
"I can count on one hands the amount of the times we've not turned up this season. We have to take this belief and use it to help us grow.
"I've been here 18 months but the club is six months into a long-term project. We do everything within our means, we're just trying to build a squad to challenge higher up from a solid base."
He continued: "Going to Anfield is fantastic. I said to the players you could have won it but I bet you all wanted to go to Anfield, didn't you?
"It's great for the supporters, the chairman, the club.
"It could bring in new players or help improve facilities, something that will bring long-term benefit to this club.
"When the chairman took over 24 years ago we were a million pound in debt, losing a couple of hundred grand a year - now we own the ground, we own the training ground.
"Now it's a case of can we make things better? Can we make the pitch better and invest in all the things behind the scenes that means long-term we can give this club a better chance of punching above its weight."