The 36-year-old former England international is currently putting his troops through their paces at a pre-season training camp in Austria.

However, work continues behind the scenes to add further signings despite the investment the club has already made in Jonathan Woodgate, Tuncay Sanli and Jeremie Aliadiere, and Southgate has promised no news does not mean bad news.

He said: "We are working on strengthening further, but we will only bring in players who are right for Middlesbrough. These things take time.

"I understand the supporters are keen for news, but I can assure them that work is going on behind the scenes.

"They should not believe that no news in the press means there's nothing happening.

"We are still looking to improve the team. We are working on a shortlist of potential targets with the aim of bringing in a couple more players yet.

"I would ideally like to bring in any additions sooner rather than later, but I am only interested in bringing in the right people.

"We are not going to make signings for the sake of it, just to get them in early."

Boro have an interest in Manchester United striker Alan Smith as speculation continues over Ayegbeni Yakubu's future at the Riverside Stadium, but their main priority lies elsewhere.

The departures of Abel Xavier and Stuart Parnaby means they are weak at right back with only converted central defender Andrew Davies having been blooded at first team level.

Southgate has targeted AZ Alkmaar's Gretar Steinsson among others, but the Dutch club's £4million valuation of the Iceland international is way in excess of what he is prepared to pay.

He has also been linked with Charlton's Luke Young, while he is keen also to strengthen in midfield.

However, he has very specific requirements of the players he wants to attract to the club.

Southgate told Boro's official website, www.mfc.co.uk: "We are looking to bring in people who believe in what we are trying to do and achieve.

"The players in the squad we have already got have been excellent in training and I'm delighted with them.

"I'm really pleased with the two new additions of Tuncay and Jeremie Aliadiere, plus Jonathan Woodgate, of course.

"They are quality players who have already made a big impact on their new team-mates, as I expected them to.

"The mood in the camp is very positive."