Last week, when the Thorns opened their season against a very good FC Kansas City team, the ball skipped and skittered across the pitch, which really seemed like flattened plastic, criss-crossed with a confusing grid of American football lines, masquerading as turf. Seriously, that ball was flying, and the field looked like a very complicated geometry illustration. It looked like amatuer hour.

The Thorns won't have to worry about that come Sunday, when they host the Reign. The match will take place on a real-live, two-star-rated soccer pitch. The fans will fill out 14,000+ seats, the Rose City Riveters will come bearing tifo and chants, and Grant Wahl will be in the press box.

This is where the NWSL puts on its big-girl pants.

But with big-girl pants comes big-time expectations, and while they were lucky enough to come out of Kansas City with a road draw, the Thorns have yet to meet them.

Are those expectations unfair? Probably. This is a young league and a new team that's had its entire squad in the same place for a grand total of about five seconds. But the Thorns still have more potential than they showed during their uneven performance last weekend. If they do so, they should walk out of Jeld-Wen with three points.

That said, it's beginning to look like nothing in this league is going to be easy. Seattle's preseason troubles --which culminated in the awkward resignation of GM Amy Carnell just a week before the season opened-- earmarked them as a struggling squad with not much notable talent. Hope Solo is gone to injury. Amy Rodriguez is gone to pregnancy. Megan Rapinoe is gone to France. All those minuses add up to a very beatable team.

But Seattle made it out of their season opener --an away game against the Chicago Red Stars-- with a draw last week, behind some stellar play from backup goalkeeper Michelle Betos and a 10th minute goal from Christine Nairn.

With her eight saves, Betos looked fantastic against the Red Stars, but there's no doubt Alex Morgan and Christine Sinclair can beat her --if they get the ball. And if anything were noticeable during last week's match against FCKC, it was that the Thorns midfield struggled to deliver.

Granted, the midfield struggled against what is arguably the best midfield and defense in the league. The Reign are neither as consistent nor as solid as Kansas City. But nor are they as hapless as everyone thinks. As a matter of fact, the Reign midfield looks pretty formidable, especially the defense-minded Keelin Winters, for whom Seattle traded future draft picks. Well known in US Soccer circles, Winters has flirted with a consistent presence on the USWNT, captained the U-20 team, and is one of the best defensive midfielders around. Canadian player Kaylyn Kyle is no slouch either. But the player that I find most worrisome is Jessica Fishlock. Along with Betos, Fishlock clearly stood out as the star of Seattle's side last week. Fishlock works as an offensive midfielder with a hard-nosed, defensive mindset --she will aggressively tackle, but isn't just a brute. That kind of assertive play is likely to disrupt a Portland midfield that, so far, looks pretty disruptable.

The good news: Seattle's backline is beatable, and its forwards much less talented than Portland's, naturally. And of course, there's the Jeld-Wen factor.

There already are several previews that do a great job of assessing the Portland side of things, including here and here. So instead of tackling what's already been covered, this rest of this preview is going to take a look at some X factors that will come into play, specifically:

The Pitch/Midfield

The speed and chop of the pitch in Kansas City is not just a side anecdote: It threw off a Thorns team that was already shaken after giving up a shocking opening goal. The playing surface may seem like a secondary factor, but if you re-watch the match, the Thorns' passes flew faster and longer then they should have, and this team is more sure-footed than that. The turf was by no means the primary reason for the Thorns miscues, to be sure, but it contributed greatly. The two-star-rated turf at Jeld-Wen should help settle the ball and the nerves.

It had better. This midfield simply cannot afford to play poorly, as head coach Cindy Parlow Cone's possession-style philosophy relies on secure connections and long passing strings. This is no kick-and-run side --the intent is to maintain possession in order to provide quality delivery to Alex Morgan and Christine Sinclair, so that the superstar strikers can do their thang. The Thorns looked fairly adept at this during their one public preseason match, when they dominated the run of play over the University of Portland Pilots, and key midfielder and former Pilot Angie Kerr looked comfortable and able on her old pitch. But Kerr looked ineffective and somewhat lost in KC. As the primary link between the middies and the forwards, Kerr needs to come to play on Sunday.

Adjustments

Well, that is, if Kerr ends up playing where she has been, which is in that soft underbelly behind the front line but ahead of the midfield. When Parlow Cone subbed her out late in the FCKC match and dropped Sinclair into that area, the Thorns scoring threat increased, and the team cohesion improved, resulting in a solid scoring attempt and subsequent PK. Parlow Cone seems to have taken this seriously, as she has fiddled with the team's formation during practice sessions this week, including moving Kerr to the left forward (hey, the coach has been emphasizing versatility) and dropping Sinclair back into that 10 role. Don't be surprised if she alters the initial 4-4-2 we saw in the preseason and FCKC matches to something different.

That speaks to overall strategic changes, but what about in-game adjustments? I worry that Parlow Cone may be missing the mark on some things (addressed below), but her on-the-fly tinkering and half-time work so far have been spot-on. Hopefully, she won't have to resort to mid-game reactions, but her previous decision-making bodes well if she does.

Intensity and Conditioning

In the only two matches we've seen the Thorns play publically, they have come out deflated and flat. In the FCKC match, they did not look aggressive. They were two steps late to reacting to the ball or other players. They did not enter either match with any kind of intent to assert themselves as rulers of the pitch. And, at times, they look tired.

It is too early to draw conclusions from this tendency, and it is too early to call the lack of intensity and apparent fatigue a trend, and it is too early to lay blame for what might not even be an issue....but, these things are noticeable, and if they end up being issues, much of the fault rests with coaching.

That said, if the Thorns come out pushing hard, they will crush a less talented Reign side. Portland should take its cue as a whole from midfielder Allie Long, who seemed like the only Thorn who came to play last week. Long was the one bright spot in an otherwise lackluster vibe of that game, directing traffic, connecting passes, trying to push the pace. The rest of the team needs to follow suit.