The Blades goalkeeper was left out of the clash with West Brom on Wednesday as the Gunners press forward with talks
Arsenal are close to signing Aaron Ramsdale from Sheffield United in a deal worth up to £30 million ($41m), Goal can confirm.
The news comes as something of a surprise, with talks initially thought to have broken down between the clubs due to a difference in valuation.
Now, however, it appears Mikel Arteta is set to get his man, with the Gunners originally having started their Premier League season without adequate cover and competition for Bernd Leno.