3 things to watch for in the 2015 MLS Cup final

The final two remaining teams in Major League Soccer's postseason, the Columbus Crew and the Portland Timbers, will square off in the MLS Cup final on Sunday.

MAPFRE Stadium will play host to the 20th edition of the MLS Cup as the Crew look to repeat their heroics of the 2008 season, while the Timbers look to make history in their first-ever final appearance.

Here are three things to watch for in the 2015 MLS Cup:

The Kings of Africa: Fanendo Adi and Kei Kamara

In a year where Europe's greatest names made their way over to MLS, 2015 was largely dominated by forwards who hail from African nations.

It's not just Didier Drogba and his 11 goals in 11 games for the Montreal Impact, though the Ivory Coast captain did dominate headlines in the latter part of the year; both Portland and Columbus owe a huge debt of gratitude for the goal-scoring performances of Fanendo Adi and Kei Kamara respectively.

Adi, a Nigerian international, scored 16 goals in the 2015 regular season and another two in the playoffs, helping guide Portland to its first appearance in the MLS Cup final. He picked up a knock in the last conference championship match, but returns right on time to play against the Crew.

Kamara, a former Sierra Leone international, led the league in scoring with 22 goals - tied with league MVP Sebastian Giovinco - and has added three more in the playoffs. Kamara suffered a right leg knock in training on Saturday, and is now a game-time decision for the Crew. If they lose Kamara, it might be too big a hurdle for Columbus to overcome.

Do these two forwards have more goals in them? We'll have to wait and see.

Defensive mids galore: Nagbe, Chara, Trapp, and Tachani

These two teams will certainly do battle in midfield, an area where many matchups in MLS are won and lost, but one that will be particularly tough and hardened in this meeting, as both teams employ some very physical footballers.

Portland's duo of Diego Chara and Darlington Nagbe play in support of attacking midfielder Diego Valeri; Columbus' twosome of Wil Trapp and Tony Tchani do the same for Federico Higuain.

There will be plenty of movement with this core midfield six, which means there will also be plenty of collisions, tackles, interceptions, and scrappy, physical play as both teams contend for control of this important area of the field.

The wingers will, of course, play their part. The Crew's Justin Meram and Ethan Finlay have been perhaps the finest pair of wide players, and with right full-back Harrison Afful in support on the right, this will be where Columbus focuses its attacking intent.

But Columbus' Achilles' heel has been its susceptibility in the back four, particularly in the middle; should Portland win the midfield battle, it could be the key to victory over the Crew.

Home field advantage: who's singing at MAPFRE stadium?

The Portland Timbers never had a chance to win the hosting gig at Providence Park, since the club finished lower than both the New York Red Bulls and the Columbus Crew in regular-season seedings.

As such, the Timbers will be the away team in this MLS Cup, held at MAPFRE Stadium in Columbus, Ohio. But they won't really be the away team in the stands if the Timbers Army has anything to say about it.

The league's finest supporters have plenty of plans to make MAPFRE Stadium feel like home: they're creating a tifo for the MLS Cup, sending five sections' worth of fans to the game (some on specially chartered flights), and even shipping an entire log across the country.

Already, the Crew and its hardcore supporters - who call the Nordecke their home - have traded jabs on social media. It's getting feisty in Columbus: Keep an eye on the stands.