Spence, who can play at full-back and centre-back, is available on a free transfer after seeing out his contract at West Ham earlier this summer.
A number of clubs have been credited with an interest in Spence, but Blackburn are leading the race for the former England Under 21 international
The 24-year-old has now linked up with Blackburn for training so that Rovers boss Gary Bowyer can cast an eye over him at close quarters.
Bowyer is looking to bolster his defensive options at Ewood Park and, if Spence impresses during his stint at the club, he could be offered a deal by the Championship side.
Spence is set to feature in Blackburn's pre-season game against Bury on Wednesday night as he will look to boost his chances of winning a deal at Ewood Park.