Arsenal's move for Pierre-Emerick Aubameyang continues to be in doubt despite £55.5m agreement

Arsenal continue to struggle to get the Pierre-Emerick Aubameyang transfer saga concluded despite agreeing a fee with Borussia Dortmund.

The Gunners have finally matched the German club's demands and were hopeful of concluding the deal before deadline day – 31 January – but Dortmund's insistence of signing a replacement before signing off on the transfer has again put the Gabon international striker's arrival in doubt.

The Guardian are reporting that the north London club have agreed in principle a fee in the region of €63m (£55.5m, $77.8m) to bring Aubameyang to the Emirates, while the striker is said to have put pen-to-paper on a three and a half year deal worth around £180,000-a-week making him Arsenal's highest earner.

The Gunners view him as an ideal replacement for Alexis Sanchez, who joined Manchester United earlier in the month, and after having seen two bids rejected, they finally met Dortmund's demands over the weekend (28 January).

However, Dortmund's insistence that they sign a replacement before allowing the sale of Aubameyang is holding up the deal with Chelsea also becoming embroiled in the negotiations. According to BBC Sport, Olivier Giroud could have the biggest say in whether or not the Gabonese forward joins Arsene Wenger's side.

The French striker will become surplus to requirements once Aubameyang arrives with Alexandre Lacazette already on the club's books as Wenger's first choice striker. Wenger is an admirer and would rather he stay until the end of the season, but Giroud knows that he has to leave if he has to play regularly and ensure he is part of the France squad at the World Cup in Russia this summer.

Dortmund were open to taking Giroud as part of the deal to bring Aubameyang to England, but the Gunners forward is said to be keen to remain in London and an offer from Chelsea, who are also looking for a striker has turned his head towards the Blues.

Giroud becoming unavailable has seen Dortmund making an approach for Chelsea forward Michy Batshuayi, who is said to be open to a move to Germany, however the Blues will only let him leave if they land a replacement.

They have failed with moves for Andy Carroll and Edin Dzeko and have been linked with a number of other forwards. Chelsea and Giroud are keen on the move, but the former have baulked at Arsenal's reported £30m - £35m valuation of the Frenchman.

Antonio Conte is desperate to sign a striker and if a move for Giroud fails, he has enquired about the availability of Tottenham Hotspur's Fernando Llorente with Batshuayi moving in the other direction. The Belgian, however, is said to have rejected that idea as he will not be guaranteed regular first-team football owing to the presence of Harry Kane.

Therefore, Arsenal's ability to sign Aubameyang rests on Giroud's next move and the Gunners accepting a lower fee for their striker and in turn strengthening one of their main rivals. The report claims that Dortmund will not sanction the sale of the Gabonese forward – despite the agreement – if they do not sign a replacement before the 23:00 GMT transfer deadline of 31 January.

Arsenal have thus far signed two players in Janaury - Henrikh Mkhitaryan from United and Konstantinos Mavropanos from Greek side PAS Giannina.