Rio Ferdinand branded Liverpool's purchase of Luis Diaz as the signing of the Premier League season earlier this week.

The Colombian forward has been electrifying since signing in a £37.5m deal from Porto in January.

Ferdinand said of Diaz on Vibe with Five, per TEAMtalk: "He has just been a breath of fresh air.

“You watch him play, on the ball he’s brilliant. But his reaction when they lose the ball is unreal.

“He’s like a trigger, bang, go go and get it back. For those reasons, he’s the standout signing of the season for me.”

But has he been the signing of the season?

WhoScored have crunched the numbers and named the 10 best signing of the season, purely based on their ratings in the 2021/22 season.

And there's a few surprises. View the top 10 below:

10) Hassane Kamara (Watford) - 7.02

Kamara has made 16 appearances for Watford this season and has statistically been their best performer.

Hassane Kamara has been one of the signings of the Premier League season, according to WhoScored
WATFORD, ENGLAND - APRIL 30: Hassane Kamara of Watford after the final whistle during the Premier League match between Watford and Burnley at Vicarage Road on April 30, 2022 in Watford, England. (Photo by Richard Heathcote/Getty Images)

WATFORD, ENGLAND - APRIL 30: Hassane Kamara of Watford after the final whistle during the Premier League match between Watford and Burnley at Vicarage Road on April 30, 2022 in Watford, England. (Photo by Richard Heathcote/Getty Images)

9) Bruno Guimarães (Newcastle) - 7.06

It took a short while for Guimarães to break into Newcastle's starting lineup but he's been brilliant since becoming a regular. He's scored four times and assisted a goal in eight starts.

8. Philippe Coutinho (Aston Villa) - 7.08

Coutinho has scored four times and recorded three assists since joining Villa on loan in January.

Philippe Coutinho has been one of the signings of the Premier League season after moving from Barcelona to Aston Villa on loan
BIRMINGHAM, ENGLAND - APRIL 09: Philippe Coutinho of Aston Villa during the Premier League match between Aston Villa and Tottenham Hotspur at Villa Park on April 9, 2022 in Birmingham, United Kingdom. (Photo by Marc Atkins/Getty Images)

BIRMINGHAM, ENGLAND - APRIL 09: Philippe Coutinho of Aston Villa during the Premier League match between Aston Villa and Tottenham Hotspur at Villa Park on April 9, 2022 in Birmingham, United Kingdom. (Photo by Marc Atkins/Getty Images)

7. Rodrigo Bentancur (Tottenham Hotspur) - 7.10

Per Sky Sports, Tottenham paid up to £21.5m for the Uruguayan in January. He's been worth every penny.

6. Jack Grealish (Man City) - 7.13

Now this is a surprise. Grealish has certainly not lived up to expectations since his £100m move from Aston Villa, contributing to just four goals in 23 games. But his overall rating suggest Grealish has been better than what most people think.

Jack Grealish has been one of the best performers of players signed in this Premier League season
LEEDS, ENGLAND - APRIL 30: Jack Grealish of Manchester City looks on during the Premier League match between Leeds United and Manchester City at Elland Road on April 30, 2022 in Leeds, England. (Photo by Michael Regan/Getty Images)

LEEDS, ENGLAND - APRIL 30: Jack Grealish of Manchester City looks on during the Premier League match between Leeds United and Manchester City at Elland Road on April 30, 2022 in Leeds, England. (Photo by Michael Regan/Getty Images)

5. Conor Gallagher (Crystal Palace) - 7.13

Gallagher has been sensational for Crystal Palace, scoring eight times and recording three assists from midfield. Unfortunately for Palace, he's only on loan and will return to Chelsea in the summer.

4. Cristiano Ronaldo (Manchester United) - 7.16

Where would United be without Ronaldo? United have struggled but he's been impressive, scoring 18 league goals in 2021/22.

Cristiano Ronaldo has been named as one of the Premier League's best signings of the season after moving from Juventus to Man United
MANCHESTER, ENGLAND - MAY 02: Cristiano Ronaldo of Manchester United during the Premier League match between Manchester United and Brentford at Old Trafford on May 02, 2022 in Manchester, England. (Photo by Catherine Ivill/Getty Images)

MANCHESTER, ENGLAND - MAY 02: Cristiano Ronaldo of Manchester United during the Premier League match between Manchester United and Brentford at Old Trafford on May 02, 2022 in Manchester, England. (Photo by Catherine Ivill/Getty Images)

3. Dejan Kulusevski (Tottenham Hotspur) - 7.19

Spurs have the option to make Kulusevski's loan spell permanent for €35 million. with 11 goal contributions in as many starts, it seems certain he'll be at Spurs beyond this season.

2. Christian Eriksen (Brentford) - 7.33

Eriksen's success has been one of the stories of the season. He's scored once and recorded two assists in seven starts for Brentford.

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1 . Luis Diaz (Liverpool) - 7.41

Diaz has been sensational for Liverpool and is playing a major role as they big to win a historic quadruple.

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