Seattle Sounders' left-back Leo Gonzalez limped off from his side's relentless playoff meeting with the LA Galaxy in the 36th minute, and has been replaced by Zach Scott.
With the score 2-2 at the break and both defences looking rather accommodating, head coach Sigi Schmid will hope the loss of the Costa Rican - and resulting reshuffle - will not prove telling.
In the veteran full-backs absence, Brad Evans moves over to left-back while Scott will operate more centrally in defence.