The Italian team have long had a presence in European rugby's elite competition, going right back to the inaugural 1995/96 season, but it is in recent years that they've really begun to make that presence felt, with significant wins coming over the likes of Biarritz and Perpignan, as well as a home draw against the Ospreys on the opening weekend of last season's tournament.
According to Rees, Treviso's introduction to the RaboDirect PRO12 has been beneficial for not only the club itself, but also, the league and Italian rugby in general.
"I've got a lot of time and respect for Treviso and what the people there have done" he said.
"Not just over the last few years since they entered the PRO12, but over the longer term. They've set a foundation in place at the club over five or six years with the current coaching group. I'm full of admiration for Franco Smith, I think he's done a great job and along with his coaches they've instilled a good ethos around strong values. That's been a real strength of theirs and they've developed some good players for Italian rugby.
"We've all seen how competitive they've been over two years in the RaboDirect. They've picked up some excellent results, including against us at the start of the season. It's a credit to everyone involved and I can only see them growing, pushing forward year in, year out."
With Leicester Tigers and Toulouse also in Pool Two, there are a number of exciting clashes in store for Ospreys fans, and Gruff insists that Treviso will play a big part in the final placings:
"They've got a very good home record, as good as most teams, and they picked up an impressive win away to Edinburgh last weekend" he pointed out.
"They've got a toughness about them and they'll be coming to the Liberty full of confidence, looking to have a good crack at us as they did the first game of the season.
"They've got Toulouse at home the following week, and regardless of how the game goes here tomorrow night, they will be confident of doing something in that game, knowing that all three teams have to visit their place.
"It's an exciting group and it's particularly exciting for Italian rugby as I've no doubt that they will believe in their ability to make a real impression in this pool. We're smart enough to look beyond any Italian stereotypes, this Treviso group have gone beyond that and the suggestion that they could pick up the occasional home win and then struggle away from home.
"All four teams in this pool will look at each other on an even keel, knowing that if they aren't at their best on any given day then they could lose, regardless of the fixture and teams involved. It's going to be an interesting competition."
Gruff spent most of last season at the now defunct Aironi, and although now back in Ospreylia, he continues to follow Italian rugby closely. He is no doubt that the introduction of Italian teams to the PRO12 has been a huge success:
"Having two sides in the PRO12 has clearly invigorated Italian rugby from top to bottom" he said.
"It's not just about Treviso, it's definitely been advantageous for Italian rugby that there's another outlet, another professional team, in the PRO12. Obviously I was involved for a while in Aironi and I've got a lot of time for what they achieved there. There were a lot of good players developed there in a short time, and making the transition from Italian club rugby to top end Celtic and European rugby.
"You've seen players like Venditti, Tebaldi, Trevisan, Favaro and De Marchi, they've come through directly as a result of what's happened over the last couple of years in Italian rugby and really started to give the national team some strength in depth.
"It's not just about the opportunity for younger players, the older ones are back playing in Italian rugby also, Bortolami, Bergamasco, Perugini. They are people who've been there and done it, been great stalwarts of Italian rugby, and having them back in the domestic game is having a positive influence."
While rugby has traditionally fallen way down the sporting pecking order in Italy, from his time in the country Rees believes that the sport can continue to grow in importance, saying:
"It's indisputable that they are hindered by the fact that as a national sport it is way down the pecking order. If you pick up the Gazetta, the national sport paper, rugby generally has a footprint on the last but one page where you've got wall-to-wall football, volleyball, handball, basketball, a host of different sports before that. That's a real challenge.
"It's not big in schools so they have to invest in the club set-up and that can be a strength. Players can come through a pathway at their club that brings them through to a level beneath Zebre and Treviso. They've got to consolidate and build on that, not just picking players from 16 and above, but looking at 11 to 16-year olds.
"I think the success of Treviso can be an inspiration. Treviso in the northeast is a real strong brand, they're doing a really good job of recruiting and developing talent, with a strong ethos of coaching that is helping them to really establish the club as a force in the wider European game.
"There are pockets of Italy where there are some real strong footholds, and that is starting to take shape. Aironi as a brand were beginning to reach out across the northwest of Italy and took games to Milan where they had a crowd of close to 10,000 for a Heineken Cup game.
"Italian rugby can continue to grow and I believe that there is a bright future for the sport there. With the population bases it's frightening to think of what they can achieve."
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