Turkey striker Tuncay Sanli has completed his move to Middlesbrough after being granted a work permit.
The 25-year-old agreed a four-year deal late last month and then returned to his native country to wait for his application to be processed.
Tuncay joins on a free transfer from Fenerbahce and is expected to join up with his team-mates in time to fly out on the club's pre-season trip to Austria next week.
The news is a further boost for Boro boss Gareth Southgate, who is confident he has significantly strengthened his squad during the summer.
Boro unveiled former Arsenal striker Jeremie Aliadiere on Tuesday and with Tuncay also on board as well former Real Madrid defender Jonathan Woodgate making his loan deal permanent, Southgate is delighted with the business he has done so far.
The recruitment process is set to continue, with AZ Alkmaar's Iceland right-back Gretar Steinsson and Manchester United striker Alan Smith though to be targets.
Southgate said: 'All I can say is we are actively looking to improve the team and improve the squad. We have been watching several different players in different positions.
'Obviously at right-full-back, we have lost Abel Xavier and Stuart Parnaby, and Tony McMahon is still recovering from a broken leg, so we are very short of cover and competition in that position, although we have some good youngsters coming through.
'I still feel we need to add a couple of players. We are looking very much to do that over the coming weeks, and the sooner we can get them in, the better.
'But it is great to have, with Jonathan, three new signings in place already, and to know we have built already on what we did last season.'
Boro finished Southgate's first campaign in charge in 12th place in the Barclays Premier League, a creditable return after the rookie manager was thrown in at the deep end.
However, while that may have been satisfactory last time around, he is looking for a progression, and that is fuelling his summer spending plans.
Southgate said: 'I said last season, I had a look at things, I had a look at the league and where we were, and I feel as a club, we need a challenge, we need to be challenged more.
'We have established ourselves as a Premier League club over the last six or seven years, but we have only had the one top 10 finish in that period of time.
'We finished 12th last year, which is a good platform for us, but I want to challenge all the players now - and I think they are ready to be challenged.
'They want the challenge. There are lots of young, hungry lads in there and it is an exciting time for us.'
