When Real Salt Lake coach Mike Petke substituted striker Yura Movsisyan in for winger Jefferson Savarino on Saturday night, RSL shifted to an attack-oriented formation.

Houston was down a man after Alex was sent off with two yellow cards in the 65th minute, and Real Salt Lake had to find a way to penetrate Houston’s defense.

“The one thing I honestly didn’t project was Houston to come in a sit as deep in the way that they did and waste close to 7 or 8 minutes the whole game with slowing the tempo up,” Petke said. “But they did what they had to do to get a result.”

In the end, RSL’s adjustments didn’t result in a goal. It came away with a scoreless draw at home, along with the realization that opposing teams had changed their approach to matches at Rio Tinto Stadium. No longer were they coming in trying to bully a struggling team on its home field.

“We just need to figure out how to play against teams when they come in here and play like that,” goalkeeper Nick Rimando said. “Last week [against Columbus] we had five in the back playing against us, this week Houston sat back quite a bit. But we still had chances, and everyone in this room knows that we should have won that game.”

With his three substitutions, Petke first replaced holding midfielder Sunday Stephen with an aggressive winger in Brooks Lennon. Then he swapped Savarino for Movsisyan, before inserting attacking midfielder Sebastian Saucedo in late for defender Chris Wingert.

RSL pulled wingers Joao Plata and Saucedo to more central positions and played with two forwards up top and while the team continued to create chances — finishing with 21 shots — no shots were on frame.

“We came here to wait for RSL’s game proposition,” Houston coach Wilmer Cabrera said through a translator. “They are at home and we know how dangerous they can be here with their speed, the altitude, the space.

“We waited a little to see what they were proposing. When we were able to have the ball we were also able to attack them with speed and give them some trouble. At the end we obviously had to defend more and more because we were a man down.”

RSL already was having trouble against Houston’s packed-in defense at even strength, and the Dynamo leaned even more heavily on that approach when it went down to 10 players in the second half.

After collecting three points in a three-match homestand, RSL heads out on the road for games at D.C. United and the Montreal Impact. The team won its past two road matches — at Portland and at Los Angeles — by a combined 10-3.

“Obviously we’d still prefer to play at home,” Wingert said, “but I think what tends to happen is when we go away the other team tries to come out and attack us, and that opens the game up so it allows us to, if we’re playing well and we’re sharp, to create some chances and get after them. As opposed to once in a while when we’re not at our best and a team comes in and gets good numbers behind the ball it’s hard to break down.”