Andy Robertson talks about his early days at Celtic and Queen's Park

Andrew Robertson says he was "miserable" for his first three months at Liverpool as the left-back adapted to life under manager Jurgen Klopp.

The Scotland captain joined from Hull in an initial £8m deal in July 2017.

But he had to wait until the end of the year to earn a regular place in the side after an injury to Alberto Moreno.

"It was hard at the time as I was not used to not playing and it was something very new to me. I didn't deal with it as well as I could," he said.

"I did struggle, and I was probably not the best to live with in the house, but it is hard because you are putting on a brave face on the training ground thinking you need to work hard to get in the team, but when you come home and start thinking about it and getting annoyed and frustrated, it goes into your family life."

Robertson, 24, was playing as an amateur in Scotland's fourth tier as recently as 2013 before joining Hull in July 2014, following spells with Scottish League Two side Queen's Park and Dundee United in the Premiership.

He caught Klopp's eye at Hull, despite the Tigers being relegated back to the Championship after a single season in the top flight.

"When you play for any club and you hear Liverpool are interested you get excited about it, and I was no different," Robertson told Football Focus. "I managed to keep level-headed. I was very realistic about it."

'Players don't control price tags'

Andrew Robertson made his Liverpool debut against Crystal Palace in August 2017

Robertson is now firmly established as first-choice left-back under Klopp, and was named captain of his national side in September.

Former Liverpool centre-half Mark Lawrenson said after Robertson helped the Reds reach last season's Champions League final that he had become a £40m player.

"People are saying £8m in this day and age is nothing, and the way the market is going it isn't, but I don't really look at price tags because players can't control them," said Robertson, who made his Scotland debut as a 19-year-old in March 2014.

'That's when I felt that I really belonged'

Robertson had to bide his time at the start of his Liverpool career, with Spaniard Moreno holding the left-back spot at the start of the 2017-18 season.

"[Klopp] played me in a couple of games and the frustrating thing was that I felt like I did quite well. He said I did do well, but I still wasn't quite adapted to his way of playing," said Robertson.

"Now I look at the performance I put in against Crystal Palace and I think a lot of people said I played well, but there were things I did wrong in terms of the way he wants us to play.

"It was just about being patient. I did have a few chats with the manager, but it was never crucial or make-or-break."

Robertson's breakthrough is widely held to have come in Liverpool's thrilling 4-3 league win over Manchester City in January, although the left-back feels it was the FA Cup victory against Everton a week earlier.

"I felt like I played well against Everton and I felt the fans started to recognise me a little. Obviously the Man City game being the next game helped as well, as my confidence was sky high," said Robertson.

"That was two really good performances, and from then I just took the confidence and I felt that I really belonged."