Atlanta United FC is heating up, and that likely does not bode well for the rest of MLS.

The reigning league champion will aim for a fourth consecutive victory Sunday, while also looking to remain undefeated against visiting Orlando City SC.

Much has been made about the slow start Atlanta (4-3-2) endured, going 0-2-2 out of the gate before winning at New England on April 13. Chalk it up possibly to a championship hangover or the pressure that comes with being the hunted, but Atlanta appears to have righted the ship while outscoring their opponents 6-0 during this current three-match winning streak.

"It starts with team spirit and belief," first-year MLS coach Frank de Boer told Atlanta's official website. "Five and six weeks ago, we were really needing to get together and understand each other on both sides. From there on, we've made some very good progress.

Atlanta's resurgence continued with a 2-0 home victory over a solid Toronto FC club Wednesday night. Josef Martinez assisted on goals by Hector Villalba and Julian Gressel as United delivered a second straight home victory.

"This is what you want," de Boer added. "Of course, we can improve and we have to improve, but it's a big step forward against a very good team and a very good opponent."

Atlanta last posted four consecutive clean sheets in September 2017, and might be in for another solid defensive showing while trying to improve on its 4-0-2 all-time mark versus Orlando (3-4-3).

City has scored more than one goal in game only twice in 2019 and was blanked for the first time this season, 2-0 by Toronto FC last weekend in its most recent contest. It also has not helped that star striker Dom Dwyer (three goals in 2019) has failed to score in any of the last five games.

"The biggest thing for us is (that) our belief doesn't waver in the players, whether somebody scores or doesn't score," coach James O'Conner told the MLS official website. "For us, our belief in the players doesn't fluctuate, sort of, by game. Our belief is there, we expect them to try really hard and to perform what we're asking them to do."

Dwyer has two goals with an assist in five career games versus Atlanta, but none of either in the last three meetings. Martinez, meanwhile, has a whopping six goals and an assist in four games against Orlando.

Though the series between these two clubs has been one-sided, both consider their meetings as a type of rivalry or derby matchup considering their proximity and southern status that excites the respective supporter bases.

"A special opponent," Gressel said of Orlando. "But we have to win. That's it."