Hardest thing is knowing you're no longer at your best - Rooney

The most difficult thing as a footballer is to know when you are no longer the player you once were, believes Wayne Rooney.

The former striker spent 13 years at Manchester United after joining them from Everton for £27m in 2004.

Rooney played 559 times for United, scoring 253 goals, and won five Premier League titles, plus the Champions League, Europa League and FA Cup.

However, he decided to move on in 2017 at the age of 31, returning to Everton.

"The hardest thing for a player is to understand you may be not at the level you were," Rooney said on The Wayne Rooney Show.

"I did it at Manchester United when Zlatan Ibrahimovic came in and I wasn't playing. I wanted to play so I left straight away. I accepted it."

Similar to Rooney's situation, Mohamed Salah will leave Liverpool at the end of this season after nine years at Anfield.

The 33-year-old forward has been a key figure for the Reds and helped them win two Premier League titles, the Champions League, Fifa Club World Cup, Uefa Super Cup, FA Cup and two EFL Cups, as well as the Community Shield.

However, he has not been as effective this season by his own high standards.

Salah will play under 30 Premier League games in a season for the first time since joining Liverpool and is on course for his first campaign without reaching double figures for league goals scored, with seven and six assists.

"I said this since the start of the season, age gets to us all and your legs go," Rooney added.

"I think that's happened to Salah this season and Virgil van Dijk hasn't been the same this season. They are the leaders in the dressing room. It's hard for the other players to go and leave their mark or become the leaders.

"I don't think he [Van Dijk] will [leave] but you've seen players when they've stayed there for too long."