Tom Court, Ed O'Donoghue, Stephen Ferris and Paul Steinmetz are all promoted from the bench, while Ulster Captain Rory Best and strong back row David Pollock both return from injury for this crucial clash.
Darren Cave and Cillian Willis are given the nod ahead of Rob Dewey and Paul Marshall who have both been dropped from the squad.
Williams explains his selection policy for this fixture:
"The changes I have made are all based on performance, apart from Kieron Dawson. Kieron was exceptional last week and has been our best player lately, he is on the bench only because we are giving him a rest from the starting line up this week."
"It's great to have Paul Steinmetz back to full fitness, he had an operation during the summer and we are so pleased to finally get him back on the pitch. I thought Paul played well against the Ospreys and provided quality leadership on the pitch."
"Darren Cave is back in the team, he is very strong defensively. We tried a different centre partnership against the Ospreys and it didn't work, so we are going to see if Cave and Steinmetz will work tomorrow night."
"Timoci needs a break, he has been starting in every game and I want to give him a rest on the bench" continued Williams.
The Ulster Coach knows what to expect against Edinburgh and has been keeping a close eye on them recently:
"Edinburgh are a very good side, Andy Robinson is a world class coach and their defence has improved enormously under his direction. They had a great win over the Scarlets a few weeks ago and played some high quality rugby against the Dragons at the weekend. They know our form has been poor of late, and will be coming over here looking for a win."
It's no secret that Ulster have not had the best start to their Magners League campaign, but following on from some stern words with his squad on Monday, coach Matt Williams is realistic about his side's performance:
"The team are all really looking forward to the game tomorrow night; we want to make amends for what happened in Swansea. We all know our performance was below standard and are looking forward to putting things right."
"The team really need their supporters over the next few months. They are going through a hard time and need the Ulster supporters to get behind them and will them to a win. I would love to see that Ulster spirit in the support throughout the province."
Tickets are still on sale for this fixture and can be purchased online at www.ulsterrugby.com, over the counter at Ravenhill Monday to Friday from 9pm to 5pm, over the telephone 028 9049 3222 Option 2 or through any of our ticket outlets which are listed below.
Ulster Rugby has also extended the popular Student rate of "tickets for a tenner" this week due to high demand. Tickets can be purchased from Ravenhill until 4pm on Friday as long as you have a valid student card.
Ulster Team: (15-9) B Cunningham; C Schifcofske, D Cave, P Steinmetz, A Trimble; N O'Connor, C Willis; (1-8) T Court, R Best (C), BJ Botha, E O'Donoghue, R Caldwell, S Ferris, D Pollock, R Diack
Replacements: (16-22) N Brady, J Fitzpatrick, C Del Fava, K Dawson/M McCullough, I Boss, I Humphreys, T Nagusa
Ulster Rugby Ticket Outlets
In Sport - 15 Frances Street Newtownards 02891 813 811
SS Moores - 6 Chichester Street, Belfast 02890 322 966
Athletic Stores - 41 Queen Street, Belfast 02890 320 491
Eden Park - 613 Lisburn Road, Belfast 02890 687 622
Euro Sport - 84 Antrim Street, Lisburn 02892 665 549
Donaghy's Sports - 25-31 Newry Street, Banbridge 02840 662 750
Style N Sport - 20 Church Street Ballymena 02825 645 371
Podium 4 Sport - 40 Montgomery Road, Belfast 02890 701 333
Overplay Sports - Unit 4 Keeburn Industrial Estate Woodburn Road Carrickfergus (opposite Carrick rugby club) 02893 362 828
Douglas Menswear - Unit 8, Bedford House, Bedford Street, Belfast. 02890 332 277
Game On Portadown 02838350598
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland