London Welsh are the pool leaders, with three wins under their belts. Only three points separate the two teams, so Friday's encounter promises to be an exciting match.
The Ravens will be captained by hooker Nigel Brady, a recent Ireland Wolfhounds debutant, in a front row which includes Ireland international duo Tom Court and Bryan Young.
The second row partnership of Ryan Caldwell and Neil McComb has been retained. In the back row, Willie Faloon replaces David Pollock at openside flanker.
The changes in the backs see Paul Marshall come in for Cillian Willis at scrum half and promising Belfast Harlequins centre Michael Allen get the nods at outside centre, with Mark McCrea switching to full-back.
An experienced replacements bench has been selected, including the likes of Ed O'Donoghue, Ian Humphreys and Darren Cave.
Commenting on his captaincy role and Friday's game, Nigel Brady said: "I am delighted to be captain on Friday night, it is a massive game for us.
"We have to win, it's as simple as that. We know London Welsh are a quality side, they are unbeaten in the competition, so this game will be our biggest challenge to date.
"It would be great to get a big turn-out on Friday night, and get the famous Ravenhill support behind us.
"We all know that we really need to make our home advantage count, and go all out to win the game. Both teams like to run the ball and play a bit of rugby, so it should be a good show."
Ulster Rugby Season Ticket holders can use their exclusive discount for Friday's game at Ravenhill.
Tickets for the Promenade, Terrace and Main Stand are priced at just £5 each for Season Ticket holders and any junior Season Ticket holders go free.
To avail of the exclusive discount; call into the Ravenhill Ticket Office (Monday to Thursday, 9am-5pm; Friday, 9am-4pm) or call the Ticket line on 028 90493 222, Option 2 (Monday to Friday, 9am-12pm).
The special Season Ticket offer is not available on the gates, tickets must be purchased before 4pm on Friday.
Tickets are also available for non-Season Ticket holders, priced at: £10 (adults) and £3 (children) for all areas.
Tickets are available from the Ravenhill Ticket Office (Monday to Thursday, 9am-5pm; Friday, 9am-4pm) and the Ticket line on 028 90493 222, Option 2 (Monday to Friday, 9am-12pm) or by clicking here.
Tickets will also be available to purchase on the gates at Ravenhill, from 6pm on Friday, priced at £10 for ddults and £3 for children.
ULSTER RAVENS (v London Welsh): Mark McCrea; Tommy Seymour, Michael Allen, Ian Whitten, Timoci Nagusa; Niall O'Connor, Paul Marshall; Tom Court, Nigel Brady (capt), Bryan Young, Neil McComb, Ryan Caldwell, Thomas Anderson, Willie Faloon, Robbie Diack.
Replacements: Andi Kyriacou, Alan Whitten, Ed O'Donoghue, David Pollock, Cillian Willis, Ian Humphreys, Darren Cave.