Things just became tougher for the Chicago Cubs in the ultra-competitive NL playoff race.

The Cubs woke up Thursday morning with the league’s second-best record at 63-45, just one game behind the Brewers (in both the division and for the No. 1 playoff seed).

Some of the contenders around the Cubs made some big moves to enhance their roster ahead of the MLB trade deadline.

[MORE: MLB trade grades: How Cubs’ Michael Soroka deal was rated]

The Philadelphia Phillies, New York Mets and San Diego Padres — three teams currently in NL playoff position — all made major splashes in acquiring elite-level high-leverage relievers.

The Phillies pulled off possibly the move of the day Wednesday, prying closer Jhoan Duran from the Minnesota Twins.

The Mets acquired St. Louis Cardinals closer Ryan Helsley, and he now could serve as an elite setup option to closer Edwin Diaz.

And then the Padres pulled off a stunner, acquiring fireballing closer Mason Miller from the Athletics in a trade that bolsters the back end of San Diego’s bullpen.

Those impact deals could pay huge dividends for their respective teams down the stretch — and in October. The Cubs’ potential path to the World Series could go through any of these squads.

The Phillies’ main weakness was their bullpen, especially with Jose Alvarado currently suspended and ineligible for the postseason. Acquiring Duran, who has a 2.01 ERA and a fastball that averages over 100 mph, is a huge move to bolster that group.

A dynamic bullpen makes the Phillies even more scary in the postseason. They already have possibly the best starting rotation in the game and a lineup that features stars such as Bryce Harper, Trea Turner and Kyle Schwarber.

The Mets completely remade their bullpen this month. In addition to the Helsley trade, they dealt for veterans Tyler Rogers and Gregory Soto.

The Padres already had a strong bullpen — three relievers were named to the NL All-Star roster — but adding Miller makes the group elite. They also added talent to their lineup in a deal with the Baltimore Orioles, reportedly acquiring first baseman Ryan O’Hearn and outfielder Ramon Laureano.

Two full months of baseball remain, so any of these teams could wind up falling out of playoff position by the end of September. And the Cubs need to focus on themselves first, as they’re locked in a tight race with the Brewers for the division.

But this Cubs team also has their sights set on a deep playoff run and a possible World Series trip. In order to reach the Fall Classic, they will have to beat some of these teams and contend with these new high-powered bullpens.

In a bit of good news, the teams directly ahead (Brewers) and behind (LA Dodgers) the Cubs in the race for the NL’s top seed had relatively quiet deadlines.

The Brewers acquired catcher Danny Jansen in a trade with the Tampa Bay Rays and right-hander Shelby Miller and left-hander Jordan Montgomery in another deal with the Arizona Diamondbacks.

Milwaukee already has William Contreras at catcher, but Jansen provides solid depth and allows the Brewers to potentially play Contreras at DH at times. Miller is on the IL with a forearm strain, though he flashed a 1.98 ERA with an 0.96 WHIP in 37 games before that. Montgomery had Tommy John surgery, so he will not pitch this season.

The Dodgers acquired Illinois native Brock Stewart in a deal with the Twins. The veteran right-handed reliever is having a good year in the bullpen (2.38 ERA, 10.9 K/9), but it’s not the big swing some other NL contenders took this week to augment their bullpen. LA also shipped right-hander Dustin May just before the deadline.

The Cubs, meanwhile, added to the pitching staff Wednesday night with trades for veteran starter Michael Soroka and reliever Andrew Kittredge, and added two more players in utilityman Willi Castro and left-handed reliever Taylor Rogers on Thursday. Those four new players will mix into a Chicago roster that will hope they provide a boost to October glory.