A date has now been set for the game, which will take place at Franklin’s Gardens on Sunday, August 31, with a 3pm kick-off.
Diggin’s testimonial year has been used to raise funds for local charity Niamh’s Next Step and a golf day, which was attended by former England cricketer Darren Gough as well as a number of the Saints first team, took place on Saturday.
And it is hoped Northampton fans will now turn out in force to watch Reihana, Smith and many more in action at the Gardens.
“I’m really looking forward to it,” said Diggin, who scored 62 tries in 148 appearances for Saints after coming through the club’s Academy.
“We’ve managed to get the likes of Tom Smith, Bruce Reihana, Johnny Howard, Darren Fox, Jon Phillips, Ben Jones, Mark Hopley, Ian Vass and loads more to play.
“It’s been tough to organise because the Gardens pitch got torn up at the end of last season so we had to delay it.
“We also had to wait for the fixtures to come out for the first team so we could get a date set when no one had anything on, but it’s been sorted now.”
Tickets for the event can only be bought on the day and will be priced at £10 for adults and £1 for children.