Andrew Robertson has described Liverpool team-mate Luis Diaz as "special" after the Colombian helped fire the Reds into the Champions League final.

Diaz arrived at Anfield in January after completing a move from Porto worth a reported initial fee of £37.5million (€45m), with a further £12.5m (€15m) in add-ons, and he has played a key role in Liverpool's pursuit of an unprecedented quadruple.

Despite holding a 2-0 advantage heading into the Champions League semi-final second leg against Villarreal, an out of sorts Liverpool found themselves 2-0 down and level for the tie at half-time in El Madrigal on Tuesday.

However, Diaz was introduced by Jurgen Klopp at the break and his presence immediately raised the levels of his team, who came back to win 3-2 on the night and 5-2 on aggregate, with the Colombian finding the net himself with a header.

Speaking to Liverpool's official website, Scotland captain Robertson was quick to praise the 25-year-old and the quick transition he has made to his new home.

"He has been special," the left-back said of Diaz.

"We have tried to help him as much as we can – all of the players. We know how difficult it is coming into the club in January. We've tried with the coaches and everyone else to get him up to speed.

"He is a special, special player. With the talent he has and the will to win, he just fits us perfectly."

Diaz has five goals and three assists from 21 appearances in all competitions for the Reds so far (13 starts), and he has averaged more dribbles attempted per 90 minutes (5.16) and has a higher successful dribble percentage (61.64) than any other Liverpool forward this season.

It was a game of two halves in Spain, with Liverpool managing just two shots in the first half prior to Diaz's introduction for Diogo Jota, before having 13 attempts in the second half as they turned things around.

"It was tough to take Jots off and I think he has been excellent this season, but Luis came on and made a big difference," Robertson added. "He played on the left, he started pushing them back, started taking the ball, dribbling and everything, it was a really good half from him.

"He has been special since the day he came in, it's a pleasure to play with him and hopefully he'll only get better as well with a full pre-season and things like that.

"I believe he will get better, which is scary, but what he is producing here and now is pretty special as well."

Liverpool's appearance in the final in Paris later this month will be their third in five years, and Robertson acknowledged how tough it is to reach the showpiece event of Europe's premier club competition, which the club has won on six occasions.

"Unbelievable," he said of the achievement. "An incredibly tough tie, it's never easy, but to be in a final is never, never easy no matter what competition you are in.

"To make it the third in the space of five years is incredible from this group of boys, for us as players and fans, and everyone alike, [we] should never ever take this for granted.

"We just enjoy getting to the final. It's so hard to get to Champions League finals, especially the amount of good teams in this competition. To get to the final is an incredible feeling. It's going to be a special occasion and we are looking forward to it.

"We've got a lot of games between now and the end of the season, but our season has been extended for the right reasons and we are so happy about it. We can't wait to try to go and compete and try to make it number seven."