Mauro Rosales, FC Dallas, celebrates a goal

FRISCO, Texas – Two MLS games without Mauro Diaz for FC Dallas – zero goals scored.

The sample size may not be the biggest, but it is the biggest concern for the 2016 Supporters’ Shield winners, as they enter the second leg of their Western Conference Semifinal series against Seattle trailing 3-0, needing to essentially play a perfect game on Sunday to keep their treble dreams alive (9 pm ET; FS1, FOX Deportes in the US, TSN2 in Canada).

But even with the task seeming next-to-impossible to outsiders, especially without the one they call their “magician,” FC Dallas isn’t showing too much concern.

“It’s just been two games without Mauro, and we played against tough teams not easy to play against,” said midfielder Mauro Rosales. “We got the result we wanted in LA. Obviously what happened in Seattle was a distraction that we had for 10 minutes, and it cost us the game. But our plan was to just get the result to come here and do what we do best, which is getting the result at home.”

Many believe Rosales is a viable option to fill the void left by Diaz, who suffered a torn Achilles against Seattle in the penultimate game of the regular season. Rosales subbed in for Diaz throughout the season and is capable of the same sort of play – if not quite at the same level – as Diaz, including handling set pieces and pulling the strings offensively.

Diaz’s fellow Argentine, however, isn’t tipping his hand on whether or not he’ll be slotted in that role after the team’s out-of-the-ordinary 5-3-2 formation backfired in last weekend’s first leg.

“Obviously losing Mauro was a big factor on this team because he was a pretty important player for our team, but in my case, I’m doing what I do best and trying to help the team in all aspects,” Rosales said. “If coach needs me to start like I have, I will be able. If coach needs me for the last 20 minutes, I’m open to help the team.”

If he doesn’t start Rosales, FCD head coach Oscar Pareja would likely lean on other players to expand their roles. One of those players who has become more aggressive offensively as his career has developed is Kellyn Acosta.

But even he knows Diaz’s production is tough to replace.

“I’m not going to replicate Mauro – Mauro’s a special player,” Acosta said. “But I think I can just use my strengths and help the team as best as possible, even if I have to get the ball deeper, get the ball higher up the field if needed.”

Acosta added his game is more “box to box” and less of a No. 10 role, but said the team collectively has to find ways to press the Sounders and find the right passing lanes to strike early.

As far as how that will happen, Pareja said the gameplan is still “under construction,” though his players have hinted at going away from the 5-3-2 defensive formation that left them reeling last Sunday.

“We’ll go back to a formation more familiar with us to get more guys in the attack,” said defender Matt Hedges, who emphasized how important it will be to score early on Sunday. “That’ll be extremely helpful because for 30-something games this year, we attacked that way. It’s more familiar for us.”

Their backs may be against the wall, but it is nothing new for FC Dallas. Throughout all three of their competitions – MLS, US Open Cup and CONCACAF Champions League – FCD have found themselves in holes and successfully mounting comebacks, some of them late in the game when all seemed lost.

Still, turning around a 3-0 deficit in Leg 2 against the red-hot Sounders would be the most impressive comeback in an FCD season littered with them.

“In the Open Cup Final, we were down and came back,” said Hedges, who scored a goal as FCD erased an early 1-0 hole to beat New England 4-2 to claim their first trophy of the year. “And in Guatamala in the Champions League, we were down and came back from that. We know we can do the comeback.”