Arsenal have stepped up their pursuit of Borussia Dortmund's Pierre-Emerick Aubameyang as club officials arrived in Germany on Sunday (21 January).

Alexis Sanchez is set to join Manchester United with Henrikh Mkhitaryan going the other way in a straight swap deal after the latter agreed terms to a move to the Emirates Stadium.

Aubameyang has been earmarked as a potential signing to help compensate for the Chilean forward's departure as the Gunners are reported to have already agreed personal terms with the Gabon international.

Arsenal have also made an opening bid for the 28-year-old which was confirmed by Dortmund, reported to be in the range of €50m (£44m), but according to the Daily Mail, it was rejected by the Bundesliga side.

The Daily Mail report adds that Arsene Wenger will now increase the offer to £53m ($73.5m, €60m) with club CEO Ivan Gazidis, head of recruitment Sven Mislinstat and contract negotiator Huss Fahmy all landing in Germany for face-to-face negotiations with Dortmund.

Aubameyang, who has scored 21 goals in 23 games this season, has grown disillusioned with life at the Westfalenstadion and is expected to leave the club in January, having missed the club's last two games.

However, it is understood that the German side are also looking to include Olivier Giroud in a potential deal with Aubameyang with Wenger previously ready to offer the Frenchman as part of their initial offer.

The French manager is hoping to complete his sixth deal of the month swiftly with just nine days left in the current window, having already completed the signing of Greek defender Konstantinos Mavropanos, while allowing the likes of Theo Walcott and Francis Coquelin to leave for Everton and Valencia respectively.

Meanwhile, Aubameyang's teammate Andre Schurrle has criticised him for the unrest that he is causing with his current transfer saga.

"It hasn't been easy to concentrate on football because there's only been one topic off the pitch," Schurrle said. "We've often tried to influence him in team meetings.

"When you talk to him, he's a great guy. Everything seems ok, but you never know what's going on in his head."

Pierre-Emerick Aubameyang
Aubameyang has reportedly already agreed terms with Arsenal Lars Baron/Bongarts/Getty Images