Yesterday's 3-2 win at Sunderland cemented the Blues in third place in the Barclays Premier League and sent them into Saturday's FA Cup final clash with Everton on the back of a 13-game unbeaten run in all competitions.

They would also have been preparing for Wednesday's Champions League final had it not been for Barcelona midfielder Andres Iniesta's last-gasp semi-final equaliser at Stamford Bridge.

However, Hiddink, whose temporary reign will draw to a close at the weekend, believes they need to reinforce their squad if they are going to be able to compete on all fronts next season.

He said: "It's not up to me to talk about that, but the people at this club know they must improve in depth because we have a good squad and a good team, but everyone knows that Chelsea has to compete on three roads.

"You need a squad not just of 14 or 15 or 16 players, but you need quality players all over the place.

"But that's not up to me, that's up to the new manager and the board, of course."

Dutchman Hiddink has enjoyed a successful spell in charge, losing only once in 21 games - at Tottenham on March 21 - and winning 15 times.

A 16th victory in his final game would send him back to his job as boss of the Russian national team with tangible reward.

He has repeatedly insisted he will not stay on at Stamford Bridge, but did not definitely rule out a return to English club football one day.

He said: "I said once when I was working in Spain, 'When I finish here, I will do something different, maybe related to football, but not in the flashlight of football as we are now'.

"I could not keep that promise, so I won't promise it anymore.

"But I will miss it, of course."

Hiddink will spend the next few days preparing his players for their big day at Wembley with midfielder Frank Lampard and central defender Alex back in training after missing the trip to Sunderland through injury, and only Juliano Belletti a doubt after he picked up a thigh problem at the Stadium of Light.