With Portland's approach on Sunday still something of an unknown, the following question should be answered cautiously: Who could be the biggest piece of the puzzle in an effort push RSL into the MLS Cup Final?
The first and most obvious choice is Nick Rimando. In a match in which Portland Timbers will be firing off shots with reckless abandon in a hopefully-futile attempt to claim something of a lead in the series, or at least to establish some sort of foothold early on. He'll be important in making saves at important points in the match, but will he be the most vital? A similar argument could be made for Chris Schuler or Nat Borchers, both of whom will undoubtedly be needed for their aerial prowess as Timbers flight in long ball after long ball.
Maybe we should instead look at somebody who might set the tone for the match. Kyle Beckerman is a natural choice for that player, as he'll be the player with the most time on the ball for Real Salt Lake, barring any strange tactical decisions from Jason Kreis. Being tasked with controlling the pacing of the match is something at which he excels: He can move things more slowly when a slower pace is needed and take more precautionary passes, or he can push forward himself when a more attacking slant is needed. He'll also be needed to patrol the midfield against a similarly midfield-heavy Timbers side.
But there's an argument to be made for Javier Morales, whose control in attacking areas and propensity for dropping into deep positions to influence the game from deeper positions helps put RSL on the front foot in difficult situations. Even if he is not directly involved in goalscoring play, his style can create sparks elsewhere on the pitch - whether that's through the creating of space elsewhere or simply finding the little pockets ahead of him.
There's not an easy or, indeed, clear answer. Everyone on the pitch will need to be at their best for Real Salt Lake to progress, even with a two goal lead heading in.