Bryan, 25, joined Rovers from the Broncos at the end of last season, and has also played for London’s other professional club, the Skolars.
He said: “I’m really excited about the game and I can’t wait to get stuck into them. We’re all very up for it and it will be good to go up against a few of my old mates.
“There’s extra bragging rights at stake for me and that’s always gives the games a little bit extra.
“We can take a lot of confidence from the Cup run we had last season and we know we can beat every team on our day. London are definitely there for the taking – they’ve had some tough results recently and we know we can match them so it should be a great game.
“The team that turns up best on the day will be the team that wins – and I know that we will definitely turn up for it.”
Croydon-born Bryan made 32 first team appearances, all when the capital club was known as Harlequins, making his Super League debut back in 2008.
Featherstone have form when it comes to Super League opponents in the Challenge Cup – they defeated local rivals Castleford in the competition last season, and also put in a brave display against Wigan in the next round.
They earned their place in this year’s fourth round with a 76-6 win over St Helens amateurs Thatto Heath.
Tickets for the 2013 Tetley’s Challenge Cup final which takes place at Wembley Stadium on Saturday August 24 are now on sale. Visit www.rugbyleaguetickets.co.uk or call 0844 856 1113 for full details.
Fans also have until the end of April to take advantage of a special upgraded ticket offer, which means fans who purchase a ticket for the final throughout the month will automatically receive a free upgrade to the next ticket pricing band. To take advantage of this great offer, please quote the promotion code UPGRADE01 when booking.