Leeds United have been told not to expect too much too soon if they manage to sign defender Diogo Leite.The Whites have been linked with a move for the centre-back, who is available to pick up on a free transfer after his Union Berlin exit.Leite is one of the most highly coveted free agents still available on the market right nowGettyLeeds’ German boss Daniel Farke will be more than aware of the 27-year-old, who made 23 Bundesliga appearances last season.Leite started his career in his native Portugal at Porto, before being loaned out to Braga and Union Berlin – with the latter signing him on a permanent deal in 2023.The Portuguese Under-21 international helped the club secure Champions League qualification for the first time in its history.He became a free agent at the end of his Union Berlin contract in June, and Leeds have been touted as among his potential suitors.European football expert Andy Brassell believes Leite is ‘one of the better free agents out there’, but it won’t be until the September international break when Leeds can start to reap the benefits.“He’s been so solid in the Bundesliga over the last couple of years now,” Brassell exclusively told talkSPORT.com. “I think it’s hard to leave a big club like Porto and to really knuckle down and make a good career at not one of the biggest clubs in another league, which is what he’s done at Union Berlin.“He’s been ultra reliable. He’s strong. I think he could deal with the tempo of the Premier League.“The Bundesliga is quite good prep for that as well. I think it’ll be hard for him having not had a proper preseason.“So if they’re gonna sign Leite, I would have thought it would be like sort of mid-September, until we see the best of him, but he’s definitely one of the better free agents out there.”Leite has made over 100 Bundesliga appearances but will be severely lacking match sharpnessGettyLeeds transfer newsFarke has been active in the market this summer, with Tarik Muharemovic coming in to replace Pascal Struijk.James Trafford has completed a club-record £40million switch from Manchester City a year on from rejoining the Etihad set-up.Leeds also beat out plenty of Premier League competition to pick up Harry Wilson following his release from domestic rivals Fulham.The Welsh international was one of the standout figures in the top-flight last term, scoring 10 goals and assisting seven more.However, Leeds passed on the opportunity to sign AC Milan’s Rafael Leao, who was offered to the Elland Road club earlier this month.