The Ulster forwards get in some scrummaging practice at Newforge.
In a recent interview, Ulster's stand-in skipper Harrison explained how 'forward-oriented' the Magners League is in comparison to the Southern Hemisphere's Super 14 competition.
The former Wallaby said: "As a tight forward, the league is a very difficult competition and very physical. Your lineout and scrum is paramount and in any game of rugby primary possession is important, but even more so over here as there are few opportunities to get clean possession.
"In the Southern Hemisphere you get a lot of rucks and continuous kicking so the ball is in play for much longer, whereas here your only decent attacking platform comes from a scrum or lineout."
Andrew Trimble looks on as Ulster out-half David Humphreys, who is currently the Magners League top scorer with 33 points, lines up a shot at the posts.
Mark McCall discusses tactics with his crocked captain Simon Best. The Ireland prop is continuing his recovery from the broken leg he sustained against Llanelli Scarlets last April.
Scrum half Isaac Boss, who won his first two Ireland caps during the recent summer tour, will make his first appearance of the season for Ulster on Friday.
Ulster number 8 Roger Wilson who is hoping to force his way into the Ireland senior squad reckoning in the lead-up to the 2007 Rugby World Cup. The 24-year-old, whose grandfather Harry McKibbin and two uncles, Harry Jnr and Alastair, were all capped by Ireland, made his one and only appearance for the men in green against Japan on the 2005 summer tour.
Wilson's back row colleague Neil Best was ever present at number 6 for Ireland during this year's summer tour to New Zealand and Australia.
Hooker Rory Best, who will captain Ulster against Edinburgh on Friday, made an appearance as a replacement against Australia in June - taking his Irish caps tally to four.
Neil Best claims a lineout ball - the 27-year-old flanker has scored two tries for Ireland in five outings.
The 21-year-old flanker Stephen Ferris, who was crowned Young Player of the Year at the 2005/06 Guinness/Ulster Rugby awards, offloads to Isaac Boss.
The brilliant right boot of David Humphreys which, in the previous five seasons of Celtic League rugby, has helped him tally up 621 points - 8 tries, 76 conversions, 135 penalties and 8 drop goals.
**All photos by Darren Kidd for Press Eye/Inpho Photography**