Gundogan, 24, is out of contract at the end of the 2015-16 season and Dortmund are thought to be willing to sell this summer to avoid losing him for nothing.
Bayern Munich signed Dortmund’s Robert Lewandowski without paying a penny after the Polish striker’s contract ran out.
The midfielder, who has won nine caps for Germany, has also been linked with a move to Manchester City and Arsenal but United are now close to wrapping up a deal.
Gundogan began his career with Bochum, before moving to Nuremberg. Dortmund signed him in May 2011, and he helped them reach the 2012-13 Champions League final. He scored a penalty in the final against Bayern at Wembley, though Dortmund lost the match 2-1.
He was sidelined for over a year with a mystery back problem which baffled doctors and forced him to miss Germany’s World Cup triumph in Brazil.??
If United to sign him, Gundogan will add considerable bite to their central midfield – he is a tenacious tackler. But he is also technically accomplished, and a fine passer.
He was signed by coach Jurgen Klopp – who will leave Dortmund at the end of the season – to replace Real Madrid-bound??Nuri Sahin, and he initially struggled to make an impact.
But he made the breakthrough in the 2012-13 season, helping the Bundesliga giants to their first league and cup double, and the final of the Champions League the following season.
He has scored 15 goals in 123 appearances in the Bundesliga, and one goal – that nerveless penalty at Wembley – in 20 Champions League appearances.??