The Gunners have already signed Stephan Lichtsteiner from Juventus, with the defender becoming Unai Emery’s first signing.
And according to The Telegraph, Arsenal will now sign Dortmund centre-back Papastathopoulos.
They say an agreement has been reached over a £16m deal, with the defender likely to pen a three-year contract at the Emirates.
Papastathopoulos, 29, had one year remaining on his current Dortmund contract, enabling Arsenal to complete a cut-price deal for the Greece international.
However, The Telegraph add that Papastathopoulos will not be officially announced as a Gunners player until next month.
Papastathopoulos worked with Arsenal’s head of recruitment Sven Mislintat during his time at Dortmund and the transfer chief is a big fan of the centre-half.
Former PSG boss Emery was announced as Arsene Wenger’s successor last month.
Emery is expected to have around £70m to spend this summer after Gunners transfer chiefs added £20m to the kitty.
However, Arsenal are refusing to spend big this summer to keep up with Manchester City and Manchester United.
Emery has been vocal on Arsenal’s transfer plans, with the 47-year-old revealing he plans to develop the current squad.
“I believe we can grow with the players we have,” he said.
“The objective is to work hard together and with these talented players.
“It’s very important for the club, after two years outside the Champions League, to work to be the best team in the Premier League and also in the world.”
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