The Ukrainian striker will miss Saturday's FA Cup final after following a hernia operation but the £30 million record buy has failed to adapt to the rigours of English football.

The former AC Milan hitman has looked unable to cope with the physical demands of the English game and Mourinho admitted Shevchenko has to decide whether he can overcome a poor first season at Stamford Bridge.

Mourinho said: "It is up to him. Hopefully he is not happy. I hope he is not happy with what he gave to his team. If he is not happy it is a good start."

When asked if he expected Shevchenko to be a Chelsea player at the start of next season, Mourinho replied: "He is a Chelsea player and he has a contract. If he is not happy and he wants to try everything to improve, of course.

"Sheva's season was not what everyone was thinking, including myself. In his defence he has a history of many years in a completely different culture. That can be on his side."

The contrast between the ill-fated Shevchenko and the Golden Boot winner Didier Drogba could not be more marked.

Drogba became the first Chelsea player for 20 years to lift the Golden Boot after scoring 32 goals in a season - 20 in the league.

The Ivorian endured a difficult first year at Stamford Bridge but has shown a marked improvement in subsequent seasons, culminating in runner-up spots for the Player of the Year award from both the Professional Footballers` Association and the Football Writers` Association.

The striker has shaken off the 'cheat' and 'diver' taunts to be acknowledged as one of the best strikers in Europe and Mourinho is delighted with his contribution.

Mourinho said: "I think he deserves it. To be top scorer in the Premiership, without taking penalties, is more than deserved.

"Every goal was a proper goal and I am very happy for him. I am happy he did score 20 goals and no penalties."

However, Mourinho is already fearing he will go into Saturday's FA Cup final against Manchester United with only 15 fully fit players.

After a season when Chelsea surrendered the Barclays Premiership title to United and lost out in the Champions League for the second time in three years to Liverpool, Mourinho admits he made a mistake in allowing defenders William Gallas and Robert Huth to quit the club.

Gallas left for Arsenal in a deal which brought Ashley Cole to the club while Huth was fed up of playing second fiddle to captain John Terry and Ricardo Carvalho and opted to move to Middlesbrough.

Mourinho replaced both with the ineffective Khalid Boulahrouz and it cost them dear when Terry and Carvalho collected injuries in the campaign.

Mourinho has admitted Chelsea's defensive strength in depth was weakened severely by their departures.

"The only thing we can criticise ourselves on is that in the other seasons we had a group of four central defenders," said Mourinho.

"This season, three. The fourth in the other years was Robert Huth. Imagine a fit Robert Huth this season, he would have played an incredible role.

"He would have played 35, 40 matches. But before JT, William Gallas, and Ricardo Carvalho, we had no injuries, no suspensions, no problems."

Chelsea's injury problems contributed massively to their title failure and the need to strengthen the side in all departments is already uppermost in Mourinho's plans.

But the Portuguese coach is determined Chelsea will not pay big money to land the players they want with Reading's Steven Sidwell the first target.

Sidwell is available on a free transfer after rejecting a new deal with Steve Coppell's side and, according to the Royals boss, has already left the club. His availability will suit Mourinho's plans.

Mourinho said: "There will be no big investments, we won't be involved in the big market. We don't need a lot of players, just a normal season without so many injuries."