Liverpool manager Jurgen Klopp was pleased with what he saw from Philippe Coutinho in the midfielder's first start since November as his side advanced in the FA Cup.

The Brazil international set up the only goal in a 1-0 win against Plymouth Argyle on Wednesday, his corner headed in by Lucas Leiva.

Coutinho, starting his first game since returning from an ankle injury, played just over an hour, much to the delight of Klopp.

"I'm happy, really happy. It was very important for us," he said.

"I thought 60-65 minutes was the perfect intensity for today. Good for him and good for us."

Divock Origi missed a late penalty for Liverpool at Home Park, but his team managed to come through their third-round replay.

Teenagers Ovie Ejaria, Ben Woodburn and Trent Alexander-Arnold started, while Sheyi Ojo and Harry Wilson came off the bench.

"I saw a few really good things but they still have to learn," Klopp said of his youngsters.

"We are not here to celebrate each single performance of our young players – that's what we expect, that's why they play. And then they need to get ready to be criticised. I don't care what you say, but it's important that they really listen to what we have to say.

"I liked, for example, the reaction of Ojo tonight. Everybody, maybe, with Ojo involved they expected he would have started if he was in this game tonight as one of the young players, but I was not too happy with one or two things.

"That's not to say, it's about something you need to feel and then go again. Today, I thought he made a big difference when he came on, with his speed and there was sharpness involved. He's a wonderful player but, without sharpness, it's nothing.

"I'm happy about their potential and we will do whatever we can to let it grow but they have a big job to do, too."

Liverpool are back in action in the Premier League on Saturday, hosting Swansea City.