Borussia Dortmund’s coach Juergen Klopp talks to Shinji Kagawa (left) during their training session.

Borussia Dortmund aim to make up for another ankle injury to Marco Reus with the return of Shinji Kagawa after two unsuccessful years at Manchester United.

Kagawa, 25, last wore Dortmund’s shirt in May 2012 when he dazzled in their 5-2 spanking of Bayern Munich in the cup final which completed the club’s first domestic double.

Kagawa’s return, sealed on the final weekend of the transfer period, not only delighted coach Juergen Klopp but has also boosted Dortmund merchandising as his shirt is the top seller - now also available with his name in Japanese letters.

“We knew there would be quite a hype,” Dortmund boss Hans-Joachim Watzke said, but even he probably didn’t expect the extent of it, with 10,000 Kagawa shirts being sold in six days alone.

Kagawa’s return boosts Dortmund’s finances but even more Klopp who is still without Nuri Sahin and Ilkay Guendogan, and now misses Reus as well for around four weeks after the midfielder damaged the left ankle - which had already cost him playing at the World Cup - in Sunday’s Euro 2016 qualifier against Scotland.

“He is a very, very good player who will make us even better. He can still kick the ball, and he is still the same boy,” Klopp told the Sport Bild weekly in praise of Kagawa.

Dortmund face a heavy schedule over the next weeks, starting with Saturday’s Bundesliga date with lowly Freiburg and Arsenal coming to town for next week’s Champions League group stage opener.

Dortmund lost their first home game of the league season 2-0 to current leaders Bayer Leverkusen, and were also not fully convincing in their second game when they almost blew a 3-0 lead in a 3-2 win at Augsburg.

They cannot afford to drop further points here and there if they really want to challenge almighty holders Bayern Munich for the title.

Munich, who ran away with the title in record time in the past two seasons, hope to regain their dominance after the international break, two weeks after being held 1-1 at Schalke.

Pep Guardiola’s team host winless Stuttgart which could see the debut of Moroccan defender Mahdi Benatia, and French winger Franck Ribery could also play for the first time after injury problems.

“We need to be in a position to play 90 minutes’ worth of the football we played for the first 20 or 30 at Schalke,” said captain Philipp Lahm.

Leverkusen are the only team with maximum points and host Werder Bremen in the opening match of the weekend round on Friday night.