Unai Emery insists Arsenal are looking to sign "very big, very expensive players" as the Gunners try to boost their squad ahead of the new Premier League season.
The Emirates Stadium outfit have been left frustrated in their pursuit of reinforcements so far this season having seen a series of bids knocked back or negoatiations drag on longer than expected.
Celtic have rejected two bids - the latest of which was worth £25 million ($31m) - for Scotland international left-back Kieran Tierney while Arsenal are struggling to raise the funds required to sign Wilfried Zaha from Crystal Palace.