Arsenal have reportedly been offered the chance to sign Manchester United target and Borussia Dortmund centre-back Manuel Akanji.Akanji, 26, looks likely to leave Dortmund this summer following the arrival of fellow defenders Niklas Sule and Nico Schlotterbeck. The Bundesliga club are looking to cash in while they can with his contract expiring next year, so Akanji's representatives are seeking a move away for him.