Thanks to their 3-0 win in the first leg of the series, the Seattle Sounders have control of their Concacaf Champions Cup Round of 16 series with the Vancouver Whitecaps. But control is a lot different that any sort of guarantee.

While overcoming this type of deficit is certainly rare, it's not remotely impossible either. For evidence, just look at the Whitecaps' 6-0 win over Minnesota United on Sunday.

This match throws in a few variables, as well. The biggest is that it will be played across the state at ONE Spokane Stadium, normally the home of the USL League One Spokane Velocity. Lumen Field is currently unavailable due to World Cup preparations. Other variables are the potential health and availability of various players, as the Whitecaps will likely use a lineup much closer to their actual first-choice group than they used in Leg 1 when Brian White came off the bench and Andrés Cubas was unavailable due to a suspension.

Notes

The only scenario that would lead to extra time is a 3-0 Whitecaps win.
In the case of extra time, there is no away-goals tiebreaker.
The winner of this series will face the winner of the UANL Tigres-FC Cincinnati series that will be determined on Thursday. Cincinnati currently leads that series 3-0 as it heads back to Mexico.
Stefan Frei, who is expected to start, has made 27 career Concacaf Champions Cup appearances. No MLS goalkeeper has more.
Although ECS will be in attendance, they won't have their normal assortment of flags due to Concacaf rules.