Henrikh Mkhitaryan will not make his Arsenal debut against Crystal Palace after the Gunners spent this morning fine-tuning the details of his swap deal from Manchester United.

The 28-year-old was pictured arriving at United’s Carrington training base as talks continued between Arsenal and the player’s agent, Mino Raiola, in London.

Mkhitaryan had to be registered as an Arsenal player by noon today in order for him to be eligible to play against Palace, who visit Emirates Stadium tomorrow afternoon, but Standard Sport understands the player was yet to undergo a medical at the time of writing.

The deal is expected to be completed within the next 36 hours but talks were continuing over Mkhitaryan’s wage - believed to be in the region of £175,000-a-week - and Arsenal’s insistence that a fee is included in the deal.

United would prefer a straight swap deal with Alexis Sanchez moving to Old Trafford. As Mkhitaryan was not registered in time, that means in turn that the Chile international will not be part of the United squad for their Premier League game at Burnley tomorrow.

Sanchez was forced to train away from the first-team group yesterday as he waits on Arsenal, United and Mkhitaryan to come to a final agreement.

The 29-year-old has already agreed personal terms worth an initial £350,000-a-week plus bonuses and image rights which will make him the highest-paid player in English football history.

Manager Arsene Wenger insisted yesterday that Sanchez could feature against Palace if the deal was not done in time but it would be a shock if he was involved in the matchday squad with a deal to leave imminent.

The Gunners were due to hold further talks today with Borussia Dortmund over striker Pierre-Emerick Aubameyang.

Speculation grew last night that a deal had been reached but it is understood Arsenal have not yet met the £55million valuation and it remains possible Olivier Giroud could be included in a player-plus cash deal, as first suggested by this newspaper on Tuesday.

Aubameyang’s personal terms are not thought to be prohibited with the 28-year-old expected to command a similar wage to Mkhitaryan.

Gunners midfielder Granit Xhaka believes Mkhitaryan will be an excellent addition. “I’m sure the style of play here would suit him,” said Xhaka. “Every player has their own qualities. He is a great footballer so let’s just see what happens.”

Meanwhile, Schalke announced that Leon Goretzka has signed a pre-contract agreement with Bayern Munich. Arsenal, Liverpool and Manchester United had scouted the 22-year-old midfielder but Goretzka, who was out of contract on July 1, will join Bayern at the end of the season.

“Leon Goretzka informed us earlier this week that he wishes to leave the club and join,” said Schalke sporting director Christian Heidel.

"We noted that with regret. [Bayern CEO] Karl-Heinz Rummenigge has told us that Leon has passed his medical. We are losing a very good player.”