Round one of the Rocky Mountain derby between the Colorado Rapids and Real Salt Lake is this week’s feature on “MLS Primetime Thursday” (ESPN2: 9:30 PM ET). Despite being just three years old, the rivalry is marked by “megawatt intensity,”says ESPN’s Jeff Carlisle, fondly recalling Pablo Mastroeni’s infamous on-field tirade in 2005 that drew the ire of RSL owner Dave Checketts. Checketts’ men got the better of Mastroeni and co. in last year’s series; in fact, RSL’s 1-0 victory at Dick’s Sporting Goods Park on the last day of last season is ultimately what kept the Rapids out of the playoffs.

Signs indicate that this year’s series may be just as important. As it is, the winner of Thursday’s contest will assume sole possession of first-place in the West — and the fact that both teams have a losing record says a lot about how weak the West really is. The winner will also be in pole position to lift this year’s Rocky Mountain Cup, awarded to the winner of the series each season. 

Among the other storylines worth following are the new faces in the fold for both teams, including RSL striker Kenny Deuchar and Colorado midfielder Christian Gomez; the return of former Rapid Kyle Beckerman, who spent five and a half seasons with the Denver club before being traded to RSL last season; the Royals’ terrible away record (0-3-0); and Colorado’s recent lineup shuffling since losing two straight in mid-April.