West Brom boss Roberto Di Matteo is relishing the 'spicy' derby clash with Birmingham on Saturday, saying it will have "no rules".[LNB] The clash is the first of 12 top-flight West Midlands derbies this season between the Baggies, Blues, Wolves and Aston Villa.[LNB]Di Matteo enjoyed the passion of derbies while a Chelsea player in the 1990s and he cannot wait for the games, which he believes will benefit the local economy of the area as well.[LNB]He told the Birmingham Mail: "I think derbies add spice to the games.[LNB]"Derbies have no rules. There are no favourites as far as my experience goes.[LNB]"If one team is second and you're bottom then it means nothing and they are special games.[LNB]"When I was at Chelsea our big derby was against Arsenal. Tottenham didn't always feel like a derby because we always won.[LNB]"But I think the region will be feeling the impact of having four teams.[LNB]"The number of away supporters, the income and economic activity that increases. It will have an impact on the area."[LNB]Di Matteo believes Birmingham have picked up some shrewd acquisitions in the transfer market and he has nothing but praise for counterpart Alex McLeish, whom he got to know on a corporate trip to the UEFA Champions League final last season.[LNB]The Baggies boss added: "They've signed some very good players - what a player Alexander Hleb is - and they've spent a few quid.[LNB]"Alex is a good guy. We went to see the Champions League final so we got to know each other then.[LNB]"He's a nice guy, we talked about football. He did a great job last year in the Premier League.[LNB]"They seemed to struggle to get out of the Championship but had a fantastic season in the Premier League.[LNB]"We forget that Alex, as a player, had a good career with Aberdeen. He's taken that into management."[LNB]Ex-West Brom striker Kevin Phillips, who scored 46 goals in 81 games for the Baggies, could return from injury for Blues in the clash and Di Matteo will not underestimate his threat.[LNB]He added: "I played against him when he was at Sunderland and he has a great goalscoring record.[LNB]"He scored quite a few last year so clearly he has a role to play for them still."