Mauro Diaz's injury throws FC Dallas' treble ambitions into doubt

Video via MLS: FC Dallas 2-1 Seattle (1:58)

Dallas scored two late goals to topple Seattle, and keep a firm grip on first place in the Western Conference. (1:58)

Oscar Pareja has been down this road before, trying to squeeze results out of his FC Dallas side without the services of playmaker Mauro Diaz. But in the wake of Diaz's Achilles tendon injury, Pareja will be forced to do so during the biggest, most difficult point of the season.

On Wednesday afternoon, FCD announced the extent of Diaz's injury: the influential midfielder has had successful surgery on a torn tendon in his right leg and will indeed miss the remainder of the current campaign. There's no word yet on how much he'll miss of 2017 as well.

All of a sudden, a team that was in line for a domestic treble might now have to make do with only a U.S. Open Cup for its efforts. The Supporters' Shield is still within reach of course. Dallas has to lose on the road to the LA Galaxy this weekend, and the Colorado Rapids must defeat the Houston Dynamo for FCD to miss out on that trophy.

But the MLS Cup playoffs are such that a team needs its full complement of players to prevail. Dallas already lost Fabian Castillo in midseason as he went on loan to Trabzonspor, but losing a player such as Diaz at this stage gives Pareja scant time to recalibrate his attack.

Before any talk of tactics, however, Pareja knows he must massage the psyche of a team that just lost its most important player.

"My job is to create that optimism, that things are going to be solved and that we'll find a way to do it in a different manner, instead of feeling sorry about what happened," Pareja said via telephone.

"It's part of the game and as a club, as a team and as a manager, you need to find a way to do different strategies, different structures, different performances, different formation. And obviously for the players, there should be an excitement of who can take the role and help us."

Pareja certainly has plenty of practice game-planning in the absence of the Argentine midfielder. All told, Diaz has missed 37 regular-season games since arriving in Dallas in the middle of the 2013 season. In 2014, FCD's record was 6-7-4 in games that Diaz missed. In 2015, the mark was 4-5-1. This season Dallas went 3-1-2 without Diaz.

"We're good," Pareja insisted. "In the last three years, we have been struggling with Mauro's injuries, and the guys have had to step up. Now, we need to do it again. It's certainly a challenge, but I have players here who have got points without Fabian [Castillo], without Mauro, without many of the players, and we have won games.

"This tells us that our team is a team; our team is a collective unit that just puts things together and tries to get points. That is the way I want them to think.

"That's the only way to survive, and that's the only way to grow as a club with our philosophy, and that's the only way you can keep the team in first place the last two or three years with some difficulties in terms of injuries or anything.

"It's something the boys have absorbed. We hope this time they can do it again."

But the playoffs leave no room for error, and Pareja will need to come up with a backup plan quickly. The FCD manager would appear to have two options.

The first is to slot Mauro Rosales into the playmaker role that Diaz once occupied. It has the advantage of leaving everyone else in their usual positions. The other is to go to a straight 4-4-2 with Tesho Akindele partnering Maxi Urruti up top and deploying two of Rosales, Ryan Hollingshead and Michael Barrios in the wide midfield positions.

That is the formation Pareja used for much of 2014 when Diaz missed half the regular season because of a knee injury. One potential wildcard is midfielder Carlos Lizarazo, but since arriving on loan from Liga MX side Cruz Azul, the 25-year-old has struggled with injuries, and generally been unimpressive when he has played.

What is clear is that Dallas will have to change the way it plays in Diaz's absence. FCD will be "a team that is a little bit more direct, and a team that is subtracting someone that brings ideas and light for us in the last third," and Pareja added: "We'll need a bit more muscle and more speed in transition. It's just a matter of finding the way in the particular games in the next seven matches that we hopefully have."

The magic Diaz creates in the final third, especially in dire circumstances, is precisely what separates teams come playoff time. Rosales is a veteran who has a bit of guile to his game, but look for FCD to take a grittier approach in the coming weeks.

The good news for Pareja is that the hip injury which midfielder Kellyn Acosta sustained last weekend isn't thought to be that serious, and while he won't make the trip to Guatemala for Dallas' CONCACAF Champions League clash against Suchitepequez, Pareja said Acosta is "in the equation" for the game against the Galaxy this weekend.

A result in L.A. would certainly be a major step toward shedding the emotional hangover of Diaz's injury. Regardless, the road to winning MLS Cup is now much more daunting.