Although the Gunners have reached a club-record agreement of £105 million with the Hammers, the transfer has not yet been made official.
Rice reportedly underwent a medical examination with the North Londoners on Friday, but the deal’s final wording still needs approval from the club’s lawyers.
According to Sky Sports, this approval is expected to happen within the next few days, allowing Rice to join the team for their trip to the United States.
Arsenal’s pre-season preparations include a friendly match against Nurnberg before heading to the US, where they will face the MLS All-Stars, Manchester United, and Barcelona.
Arsenal head coach Mikel Arteta aims to field a strong team during these fixtures and is also anticipating the finalisation of Jurrien Timber’s transfer from Ajax, as the player completed his medical examination on Friday. Arsenal have already spent over £200 million in the transfer window and may see further player departures in the coming weeks.