Paul Marshall will be fulfilling a childhood dream when he runs out for Ulster for the 150th time tomorrow night but the scrum-half is already looking beyond that.

The 30-year-old made his debut against Newport Gwent Dragons in September 2006 and will start in his 123rd GUINNESS PRO12 fixture at BT Murrayfield when the Irish province face Edinburgh.

Marshall, who will start alongside the versatile Peter Nelson at half-back, said: "The appearances have racked up pretty quickly over the past few years so it will be really nice to get my 150th cap this weekend.

“When you're a schoolboy you dream of playing for Ulster and to have done that on so many occasions is a real privilege.

“I've been involved in some really big games and they've always been fantastic, especially at home with our support and the atmosphere that they generate.

"It's nice to hit different milestones and when I finish playing I'll look back on some of the big occasions and take great pride in them. But for now I will just be looking forward to cap number 151, 152… and that will be the way it goes until my career ends.”

Sammy Arnold will start the game at outside centre in what will be just his second competitive start for Ulster, after Luke Marshall was ruled out with a thumb injury.

Up front, the experienced trio of Callum Black, Franco van der Merwe and Nick Williams return to bolster the Ulster pack. Captain Rob Herring, Wiehahn Herbst and Dan Tuohy retain their positions in the tight five.

With Williams packing down at No.8, Roger Wilson switches to blindside flanker, while Sean Reidy will continue in the seven jersey.

Robbie Diack is unavailable for selection after picking up a thigh injury playing for Ulster A last weekend, while Ian Humphreys could play his first competitive match of the season after returning from a hamstring injury to take his place on the bench.

As for Edinburgh, there are three changes to the starting XV that won the last league game, against Ospreys, to maintain Edinburgh's position at the top end of the GUINNESS PRO12 table.

Scrum-half Nathan Fowles moves up from the bench to form the half-back partnership with stand-off Phil Burleigh.

Captain Mike Coman stays on the blindside as Hamish Watson is promoted to the XV at openside and Nasi Manu returns from injury at No.8.

Edinburgh beat Ulster in pre-season but head coach Alan Solomons is under no illusions that meeting them in the league will prove a very different challenge.

Solomons said: "We showed in August that if we deliver a good performance we can win the game and I think that's important for us from a confidence perspective.

"Obviously a competitive match is a different kettle of fish and we'll have to be at the top of our game in order to get the result.

"We know we've got a massive game tomorrow night against Ulster – they've been one of the top teams in Europe over the last four or five years – and we're really going to have to deliver a performance here.”

Edinburgh have won three of their last four fixtures at BT Murrayfield in all tournaments, but have been defeated in their last five contests at the venue against Irish provinces.

Ulster’s last five fixtures have all been won by the home side on the day, whilst the Ulstermen’s only victory on the road since February came on a trip to Connacht in April.

Edinburgh have won just one of their last nine encounters with Ulster in all tournaments:, which was the 14-8 victory at BT Murrayfield in the GUINNESS PRO12 in March 2013.

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At BT Murrayfield, 7.45pm. Live on Sky Sports
Referee: Dudley Phillips (IRFU, 52nd competition game)
Assistant Referees: Sam Grove-White, Mike Adamson (both SRU)
Citing Commissioner: Iain Goodall (SRU)
TMO: Iain Ramage (SRU)