Following their important 2-1 win over Colorado Rapids last week, Dallas now need to get a positive result against Seattle to qualify for the play-offs.
Last week, Hyndman locked out the team's training sessions so his players could focus and it proved to be a success.
"I really thought last week, we needed something special," he said.
"I thought we needed something special for this team. They're hearing the same thing from me over and over again and of course, it's A-level, quality motivation stuff, but you can only hear that stuff so many times. So what I wanted to do was put actions into words. My action was we're going to train all week in the stadium and we're going to shut down practices because want you guys to show up and just play.
"What it did was it made the week a little special. I honestly thought last week was our best week of training since I've been here," he continued.
"It was an absolutely great week. I don't think we even took a day off, so we were focusing on just that game. Not one person cried about not getting a day off and all that kind of stuff. I thought we showed up from the first second of the game ready to play."
Hyndman has decided not to take the same approach this week, saying the fact the match is away from home didn't really fit in with his plan.
"If I did that again, maybe we lose a little bit of that plus we're not playing at home. I could have shut down practice (again this week), but I didn't think it would be necessary."