THEY might have lost their leading goalscorer when Ayegbeni Yakubu agreed to join Everton this week, but Gareth Southgate last night insisted that Middlesbrough would not be prioritising the purchase of a new striker before the transfer window slams shut on Friday.

And with North-East rivals Newcastle due to visit the Riverside tomorrow, the Boro boss has urged some of his lesser lights to become "heroes" now that the Nigeria international has gone.

Yakubu spent yesterday completing a medical on Merseyside after Middlesbrough accepted an £11.25m fee for his services this week.

His departure, which will be confirmed when Everton receive a work permit, follows hot on the heels of Mark Viduka's exit to Newcastle and means Boro have now lost a strike-force that accounted for 26 of their 44 Premiership goals last season.

Mido and Jeremie Aliadiere have arrived to help plug the gap, but the sale of Yakubu has led to fervent speculation linking the Teessiders with a number of Europe's leading marksmen.

Southgate admits he is interested in a number of transfer targets, understood to include Heerenveen striker Afonso Alves and PSV Eindhoven attacker Aroune Kone.

But with the duo's Dutch employers holding out for a multi-million pound fee, the Boro boss also insists that he will not be "held to ransom", even if that means making no more additions before the transfer window closes next weekend.

"I'm honestly not bothered," said Southgate, who has also signed Jonathan Woodgate, Luke Young and TunÃay Sanli this summer.

"You always want to improve the squad if you possibly can, but we only have a week left to do it. We have to be realistic. Will we find a particular person in a particular position in that space of time? Highly unlikely.

"It doesn't get me down. People can be as negative as they like about losing people, but we have a squad that will work hard together and in this division, outside the top four, that's what brings you success.

"Yes, we've lost a couple of good players, but we've also added several top players to our team, some of whom haven't even had the opportunity to play for us yet. We're looking forward to that challenge of everything that's ahead."

Newcastle will provide the most immediate challenge, and Southgate feels that last weekend's gritty 2-1 win at Fulham was a perfect example of what he is hoping to achieve this season.

Lee Cattermole emerged as the unlikeliest of goalscoring heroes in his first start of the season, grabbing an 88th-minute winner after Boro battled back gamely to overhaul an early deficit.

The midfielder scored two goals in the whole of last season but, with both Viduka and Yakubu having departed, Southgate is looking for a broader band of match-winners to make their presence felt.

"When we had Mark and Yak last year, I think there was a danger that the rest of the team assumed they would win the game for them," he explained.

"If you want to win matches, different people have to step up to the plate every weekend, and we have enough talented players to do that.

"The hero will be a different person every weekend, and hopefully this weekend's game will prove that. I've already told the lads they have an opportunity to go out and be heroes on Sunday. If they win, they can do pretty much what they like in the town."

As well as having lost the services of their two leading scorers, though, Boro will also be without last season's most impressive centre-halves as they attempt to record their first home success of the campaign.

Emanuel Pogatetz continues to nurse an injured knee and, while Jonathan Woodgate has returned to training after missing the opening three matches of the season, the former Newcastle defender is unlikely to be involved against his former club.

"You can say that from the end of last season going into this week, we've lost our two centre-halves and our two centre-forwards," admitted Southgate.

"But we either sulk and go home or we roll our sleeves up and say, 'Let's get on with the challenge'.

"We have a fantastic game against Newcastle to look forward to, so it's a case of 'Into the breach - let's go and get the win'.

"We know where we want to go and, if people don't want to be a part of that, it's pointless trying to drag them along with us."

Yakubu clearly didn't want to spend the rest of the season at the Riverside and, after consistently defending the striker's conduct during the summer, Southgate has admitted that his disinterested display at Wigan effectively signalled the end of his Middlesbrough career.

Having decided that the Nigerian's position had become untenable, Southgate instructed those above him to negotiate a price they deemed acceptable and, with Everton having broken their transfer record to seal a deal, the transfer would appear to have suited all parties concerned.

"In the end, we had to decide whether, emotionally, he was too far down the line for us to keep him," explained the Boro boss. "Once we did that, we had to decide on a fee we thought was acceptable.

"I have a lot of time for Yak. I think he's a lovely lad but, in the end, his head was turned by the possibility of moving on. He was a big player for us, especially last season, and in the early part of the season, his goals won us lots of games.

"I wish him good luck. I don't think there's an ounce of malice in his body and I hope things work out as he hopes."

Southgate was similarly complimentary about Viduka, who is preparing to make his first return to the Riverside since joining Newcastle in June.

"Mark is an outstanding player," he added. "He was terrific for us, especially at the end of last season. I've spoken to him since his move and, as his manager, I was grateful for what he did for us.

"He was excellent for me as a player and a character, and I enjoyed working with him. I wish him all the best, but he knows he'll get nothing but a hard time this weekend."