Ahead of Saturday afternoon’s kickoff in Seattle, Portland Timbers head coach Giovanni Savarese would have had a good idea of what to expect from Seattle Sounders FC's midfield. U.S. international Cristian Roldan has been ever-present for Brain Schmetzer’s side, and especially with Sweden’s Gustav Svensson on duty in Russia, a healthy Osvaldo Alonso was always destined to start. Like most teams, the Sounders have a clear hierarchy, not only in midfield but at other places on the field.

The Portland Timbers are proving to be different than most. Other than Diego Chara, it’s unclear who will start in the middle from week-to-week. Saturday was the latest example. Most would have bet Cristhian Paredes would be in the team’s starting XI, but when the lineups were exchanged, it was Andrés Flores and Lawrence Olum who were joining Chara. Neither of those names were a surprise, exactly, but one or two months ago, most Portland fans would have been surprised to see either get the call.

That’s the landscape into which David Guzmán and Andy Polo are likely to return. With Costa Rica and Peru eliminated from the 2018 World Cup in Russia, the two Timbers midfielders will be rejoining their club team soon. Guzmán was a guaranteed starter last season, while Polo seemed to have claimed a regular place in Saverese’s XI in this one, yet given how the Timbers have managed minutes this season, it would be a surprise to see either jump straight back into the starting lineup. Playing time not only has to be earned but, as the resurgence of Olum as a regular contributor has shown, can be claimed at any time, by almost anybody, depending on the needs to the moment.

And those aren’t the only options in Portland’s midfield. Bill Tuiloma, over the last two games, has seen time in what New Zealand fans and Marseille experts might call his best position. Sebastián Blanco, too, has spent time in a central role, as he did two weeks ago in Atlanta. Eryk Williamson made the bench for Saturday’s trip to Seattle, and Renzo Zambrano, while not currently on an MLS contract, was one of the team’s bright spots in the U.S. Open Cup victory over San Jose.

For weeks, now, we’ve been talking about the Timbers’ depth, and perhaps we’ve been going on a bit too much. But with two starting-caliber players about to return, the team’s options are going to come into greater focus than ever before. There are not only going to be starting spots at stake; there are going to be tough decisions when it comes to the last spots on the gameday squad. Your sections at Providence Park are going to debate these choices, just as your timelines on social will dissect them in light of the results.

Some of those choices will come down to the night’s formation. For most of the season, the Timbers have been playing three central midfielders, and after integrating a diamond midfield, they now have two formations that do so (the diamond as well as the 4-3-2-1). But there have been other looks, this season, that have used only two in true midfield roles. If the team ever goes back to a 4-2-3-1, their glut of central midfielders will be even more pronounced.

The formation choices, however, won’t happen in a vacuum, and as we’ve seen as players claim or lose spots, form is going to play a pivotal part. That’s been less so in the past, with the lack of squad depth allowing most starters to play through their ups and downs, but the team’s current approach has allowed Flores to slowly claim more minutes in the starting lineup. It’s allowed OIum to resurrect his first-choice relevance, and it could eventually see Guzmán or Polo back in starters’ roles.

But as Saturday 3-2 win in Seattle also showed, need in terms of specific skills could play a role in any match, with very few redundancies within the group leaving Savarese with a series of nuanced options. Guzmán has qualities in distribution that are unmatched within the central midfield core, while Polo’s work in possession, in transition and getting forward are unique. On Saturday, Flores’ intelligence and temperament may have helped win him a start, as it has in other big games, this season, while Chara’s ability to play above his normal defensive midfield role made room for an even more defensive-minded Olum. Parades, a natural box-to-box option, was dropped to the bench, but as we’ve seen throughout the season, his skillset has been preferred against most opponents.

Health also should be added to this list of determining factors, as should any other reason that might take players from the field, but as we’ve seen in the absence of Guzmán and Polo, thus far, those have been lesser concerns than in years’ past. Perhaps there will come a time this season when three, four midfielders being out will hamstring Savarese’s plans, but that’s a difficult place to find yourself when you can only play so many players at once. Chara’s early-season injury proved to be a different matter, but as Guzmán and Tuiloma dealt with knee problems and Sebastian Blanco’s been handed a thigh ailment, the team has not only been able to cope but has kept throwing out lineups that are tailored to their opponents.

Just because a couple of Timbers midfielders are injured doesn’t mean you’ll be able to predict their approach. Pretty sure about their formation? That’s fine, but what if the number six is Guzmán and not Chara? That implies an entirely different approach. Or, what if Olum is in that role, and instead of having a more shuttling presence beside him in a double pivot, there are two players in front of him, and one is Blanco? There are so many things you can know or guess right about how Portland’s midfield and still not how they’ll lineup against you.

Perhaps some can spin this variety of options as a lack of truly elite singular selections, but the Timbers’ current run hints they’re not lacking for quality in the middle. It’s the depth of that quality, and the different combinations that can complement each other, that leaves the Timbers so hard to figure out.