Former British and Irish Lion Richie Gray's absence from Scotland's World Cup training squad is his own decision, says assistant coach Danny Wilson.

Toulouse lock Gray was a shock omission from Gregor Townsend's 44-man training squad in May and was overlooked on Tuesday when Sam Skinner was ruled out.

The 29-year-old become a father to son Ostin at the end of May.

"Due to family reasons and returning from injury, he decided he couldn't commit to the World Cup," Wilson added.

"As I understand it, Gregor has been in conversation with him for a long time. Timing does come into these things at times and that's the situation. It's a personal choice which we understand from Richie.

"He's not been in the squad since I began my time with Scotland. Hopefully that will happen in the future, but we'll see."

Gray has not played for Scotland since the win over Italy in Rome in March 2018, mainly because of back and hip complaints.

However, he ended last season by helping Toulouse to the Top 14 title and has been in "constant conversation" with Townsend, according to Wilson.

As it stands, Skinner has been replaced by Tim Swinson. However, the Glasgow Warriors lock only has until Tuesday to earn himself a place in the 31-man squad for the tournament.

Swinson, who was selected for the World Cup four years ago, can play in both the second and back rows, which Wilson said could aid his case.

"We've obviously got a decision to make around that second-row/back-row situation that Sam offered us some flexibility around," Wilson said.

"There's an opportunity for boys to perform in these games then get picked but, first of all, Tim would have to get picked and right now he's just in to train. We'll see how that goes over the next two days."