The striker, 31, is out of contract at the Riverside and is thought to be coveted by a handful of clubs, including Newcastle and Portsmouth, after hitting 19 goals this season.

Boro boss Gareth Southgate is keen to hold onto the player, but Viduka admits he has plenty to think about before he decides where he will be plying his trade next season.

He said: "We will see what happens in the next few days, but it has been one of the hardest decisions I have ever had to make and I haven't come down on one side or the other yet.

"I am a Libran and we like to procrastinate. That's what we do. We like to chill and see how things pan put.

"The situation has to be right for myself and right for the club."

Viduka insisted that negotiations had been cordial but also questioned whether Middlesbrough would offer him a satisfactory deal.

"Negotiations have been very good but whether we come to an agreement remains to be seen.

"I don't think the club want to make too much of a commitment, so both sides need to get it right.

"It will be my last real contract, so it has to be the right one. I have two choices - to stay or to try something new."