FORMER Blackburn winger Damien Duff last night admitted he's becoming frustrated by Claudio Ranieri's rotation policy at Chelsea.

Duff joined the Blues in the summer for a club record £17 million fee but he has yet to finish a game for his new club as Ranieri continues to rotate his star-studded squad.

"Sooner or later I would like to play a full 90 minutes," complained Duff, ahead of tonight's Champions League tie with Sparta Prague.

"I was gutted to be taken off after 70 minutes of Saturday's game against Spurs and it seems to be happening in every match."

Duff has been substituted in all five of his Chelsea appearances so far and he was particularly disappointed to be withdrawn at half-time against his old club Rovers recently.

"I didn't like coming off at half-time against Blackburn," said the Republic of Ireland international.

"That was a tactical change but the gaffer likes to make a change, so what can I do?"

Duff is also unhappy at being asked to play out of position with Ranieri often using him on the right instead of his favoured left-wing berth.

"It doesn't help that I'm playing in different positions in the team but I'm big enough and strong enough not to let it bother me," he added.

Ranieri -- who is known as 'Tinkerman' for the way he juggles his squad -- insists Duff will have to grin and bear the current situation, for the time being at least.

"It is impossible to keep all the players happy. I've spoken to them to explain the situation.

"If players are unhappy, it can damage the atmosphere. That's why I spoke with them.

"Everybody must accept this way. This is a new era for Chelsea. The ones who understand this will stay with us.

"If they do not understand and are not happy, then I am sorry they will stay behind in London when we go elsewhere.

"What I will say is that in my career I've never selected players on the basis of how much they cost. It's what they produce on the pitch."