When the Fire hosts the New York Red Bulls in its home opener Sunday, it will be hard not to think about the teams’ last meeting and the changes it brought.

Unless you’re coach Frank Yallop or a highly focused player.

‘‘It’s irrelevant what happened last year,’’ Yallop said.

Needing a victory on the final day of last season to make the Major League Soccer playoffs, the Fire was routed 5-2 as its leaky defense faltered at the worst time. Soon after, coach Frank Klopas and president of soccer operations Javier Leon were gone as the team tried to distance itself from an inconsistent and, ultimately, disappointing season.

The Fire has tried to do that by hiring Yallop and technical director Brian Bliss, who have rebuilt the defense and turned over much of the roster. So far, that has led to an 0-1-1 start, including an encouraging 1-1 road draw last Sunday against the Portland Timbers.

Now the new regime and remodeled team will make its Toyota Park debut against the Red Bulls, who routed the Fire in its biggest game last season. And revenge will be on the Fire’s minds.

‘‘I didn’t play in that game, but guys should be thinking about that and trying to avenge that loss,’’ midfielder Jeff Larentowicz said. ‘‘We’re a different team, and this is a new year. I think at this point we’re looking to get our first win.’’

Larentowicz is right when he says the Fire is a different team. Against the Timbers, the Fire started five players who weren’t with the team last season and played in Yallop’s preferred 4-1-4-1 formation. Younger players such as Harry Shipp, Benji Joya and Quincy Amarikwa have been given extended chances to make their case to start on a team that doesn’t seem to favor veterans anymore.

It’s possible — and perhaps likely — that those changes wouldn’t have happened if Klopas were still around. He still might be if the Fire had beaten the Red Bulls last fall. But it didn’t, and now Yallop’s in charge.

‘‘Obviously, a coaching change and a lot of new players, a lot of new personnel,’’ defender Bakary Soumare said. ‘‘We’ve addressed the issues that we want to address in terms of players, which is great.’’

One issue the Fire wants to put to bed is forward Mike Magee’s status. The 2013 MLS most valuable player hasn’t appeared yet this season because of a hamstring problem, but he made it through three practices and is expected to play for the first time.

Magee’s arrival last season helped pull the Fire from the bottom rungs of the Eastern Conference to the verge of a playoff berth. He wasn’t quite enough, of course, setting an eventful offseason into motion.

‘‘Last season, there’s nothing we can do about it,’’ Amarikwa said. ‘‘It’s really important to focus on what you can control, and that’s your preparation for the game and coming out and giving 100 percent.’’