Craig Mitchelldyer/Portland Timbers
It's a Sunday night that has been circled on the calendar for months: Darlington Nagbe's return to Portland, an MLS Cup rematch, and one of the games of the season as Atlanta United arrives to face the Timbers at Providence Park (7 p.m., TV on Fox Sports 1).

The Opposition

After tearing through the league on their way to MLS Cup last season, 2019 has been an extremely trying year in Atlanta.

The transition from Tata Martino to Frank de Boer as manager has been challenging, with a number of players openly criticizing the Dutchman's tactical rigidity at the All Star game. Pity Martinez, the club's record signing, particularly struggled to adapt to de Boer's system and fill the shoes of Miguel Almiron.

The result, for the first five months of the season, was a great deal of plodding, methodical soccer — effective enough to keep Atlanta near the top of the Eastern Conference, but a far cry from the standard they set in their first two years in the league.

In the last few weeks, though, Atlanta look like they've gotten back on track. Since losing to LAFC at the end of July, the Five Stripes have won four straight games: two in MLS play over the LA Galaxy and NYCFC, a U.S. Open Cup semifinal in Orlando, and Wednesday's night Campeones Cup against Club America, in some style.

What's changed? De Boer finally opened things up tactically, reverting to the attack-minded three-back system that Martino favored last year, and his players have responded in kind. Atlanta is playing as progressively and joyfully as they have all season — and that should scare everybody in the league, including LAFC.

One other key factor in the recent turnaround? Josef Martinez has scored 14 goals in his last ten league games. That doesn't hurt either.

The Tactics

If de Boer lets his team play — and that's no guarantee, given how conservative his instincts are — this will be an exceedingly fun game.

Atlanta in the 3-4-3, with its top players healthy, is tremendous to watch. They get width through their wingbacks, all kinds of creativity and speed through the middle of the field between Ezequial Barco and Pity Martinez, and enough athleticism in central defense to successfully go man-to-man at the back.

When it all comes together, as it did in the first half of the NYCFC game last weekend, it can be overwhelming. Nagbe acts as an anchor amidst the chaos in central midfield, and won turned in one of his most impressive performances in years on Wednesday night against Club America.

The Timbers, of course, have plenty of attacking firepower as well — and if Atlanta does use the 3-4-3, they'll have chances to play at even numbers in transition.

Brian Fernandez and Leandro Gonzalez Pirez will almost certainly clash at one point or another, but the real area to watch will be out wide. Atlanta's wingbacks are both natural wingers; if they don't spend the majority of the first 15 minutes in Portland's half, you'll know de Boer is seriously concerned about the Timbers' counter.

There are two major concerns for Giovani Savarese. One is his central defense, which is likely going to have to try to contain Josef Martinez without Larrys Mabiala. The other is fatigue. This will be the Timbers' fifth game in 15 days, and they weren't at all sharp to finish out Wednesday night's win over Chicago.

This will also, it should be said, be Atlanta's fifth game in 15 days — and they expended plenty of energy, perhaps more than expected, on Wednesday night. Josef Martinez went 90 minutes in that game, despite dealing with an adductor injury, and plenty of other starters did as well. How much will they have in the tank?

The Lineup

12 - Clark
4 - Villafaña
18 - Cascante
25 - Tuiloma
2 - Moreira
21 - Chara
22 - Paredes
10 - Blanco
8 - Valeri (C)
17 - Ebobisse
7 - Fernandez

— Mabiala will almost certainly miss out with the hamstring injury he suffered against Chicago, leaving Cascante and Bill Tuiloma as the center backs.

— Jorge Villafaña and Jeremy Ebobisse are both set to rotate back into the side at the expense of Zarek Valentin and Marvin Loría.

— Sebastian Blanco and Diego Chara, assuming they keep their places, will be making their fifth start in this 15-day stretch.

The Memory

This chance, which fell to Jermey Ebobisse, was as close as the Timbers ever came to getting on the board in MLS Cup. Other than that, it was all Atlanta.

The Pick

This should be a terrific test for both sides. It'll go back and forth, and finish 2-2.