The Seattle Sounders head into tonight’s match against Club León sitting in a strong position. Courtesy of their 3-0 win in the first leg last week, the Sounders merely need to avoid losing by three goals in order to advance to the Concacaf Champions League semifinals for the first time since the 2012-13 edition of the tournament.

But that might be understating the challenge they face against one of Liga MX’s strongest sides. Here’s what we’d like to see:

Avoid the chaos

There’s a clear primary objective for the Sounders in León: advance. The work they put in last week against the Mexican side put them in a great position to advance to the semi-finals. But the secondary objective for Thursday night seeks to answer the question, “at what cost?”

You’ve been around long enough to know that CCL is never easy. While the first C technically stands for Concacaf, the secret meaning is chaos. Just look at what happened to NYCFC this week. The Pigeons entered the second leg with a comfortable 3-1 lead over Comunicaciones FC, and even added to their lead in the first half on Tuesday night. But then all hell broke loose in the second half and the series ended 5-5, with NYCFC advancing on away goals. It’s OK if the Sounders technically lose on Thursday, but they need to avoid the chaos and control the vibes. - Mark

Score first

It’s obviously an over-simplification, but it really can’t be overstated how important it is for the Sounders to get the first goal. Not only will that extend their aggregate lead to 4-0, but almost as crucially it will give them the away-goals tiebreaker and force León to score at least five goals in order to advance. That’s not outside the realm of possibility, but it’s worth noting that León has only scored five goals or more once in the past six-plus seasons, and that was when they put up six on a backup-heavy Sporting KC lineup in Leagues Cup play last year. - Jeremiah

What to do about Yeimar?

The Sounders are probably going to be without Yeimar Gomez Andrade on Thursday night because of a sprained ankle he picked up against the LA Galaxy. Jackson Ragen stepped in on Saturday and played well in the 4-2-3-1 next to Xavier Arreaga. Brian Schmetzer may decide to change the formation and play Ragen, Arreaga, and AB Cissoko as the back three. This may make the Sounders more resolute at the back, but it makes the task in the midfield a bit harder. - Mark

Make transition opportunities count

The most obvious thing that the Sounders did well in the first leg was repeatedly creating transition opportunities. The Sounders ended up being credited with seven “big” chances in the game, almost all of them following turnovers. One can only assume that León won’t allow the Sounders quite so many opportunities in the return leg, but there’s every reason to think that they’ll get at least a few. The trick this time is to be far more clinical than they were in Leg 1. If the Sounders can finish at least one of those chances, they’ll be in good shape. - Jeremiah

Keep the counter-press going

The Sounders did very well against León last week primarily because the counter-press in the midfield was on point. The “2” and the “3” of the 4-2-3-1 often became a “5” and it overwhelmed Leon. If the Sounders choose to play with three centerbacks, they’ll lose a body in the midfield. Seattle typically plays with two central midfielders, two floating attacking midfielders, and a forward when they play with three CBs at the back. Let’s say the two attacking mids and the forward are a combination of Cristian Roldan, Jordan Morris, and Fredy Montero. It’s important that both attacking mids don’t get sucked into the middle, because when that happens the quick transition up the field likely won’t work. They’ll need to find their space and trust their teammates to win the ball back. - Mark