Bournemouth's Vitality Stadium was evacuated on Monday after an object was discovered.
Police were sent to the ground at around 1.31pm, with players and staff waiting outside the stadium while the investigation from Dorset Police took place.
As reported by The Bournemouth Echo, it was established that the object was related to training conducted at the stadium during the weekend.
A statement from Dorset Police said: 'At 1.31pm on Monday 24 July 2023 Dorset Police received a report of an unidentified item having been found at the Vitality Stadium in Bournemouth.
'Following enquiries, it was established that the item was related to some training conducted at the grounds during the weekend.'
Safety training took place at the Vitality Stadium on Sunday and a fake device wasn't taken away by mistake.
Although police were called as a precaution, everyone was back inside the stadium within ten minutes.
Bournemouth, who finished in 15th place in the Premier League last season, will start the new campaign with a home game against West Ham on August 12.
The Vitality Stadium has a capacity of 11,307 and is the second smallest ground in the Premier League behind newly promoted Luton Town's Kenilworth Road, which has a capacity of 10,356.