After the 2017 season, the Yankees decided not to retain Joe Girardi as their manager. The Yankees hired former player Aaron Boone to succeed him on December 4, 2017.
The Yankees finished their spring training in 4th place in the Grapefruit league with an 18–13 record with a.581 winning percentage.
Regular season
March
The Yankees began the regular season on March 29, 2018, with a 6–1 win over the Toronto Blue Jays at Rogers Center in Toronto, Canada. They ended up going 2–1 in the first 3 games of the season.
April
On April 20, following their loss to the Toronto Blue Jays, they had a record of 9–9, and were in third place in the American League East, seven games behind the first place Boston Red Sox. They would follow this by winning 17 out of their next 18 games which would, at 26–10, give them the best record in all of MLB. They finished the month going 16–9.
Yankees–Red Sox brawl
On April 11, 2018, the Yankee-Red Sox rivalry heated up at Fenway Park when the Yankees and the Boston Red Sox game broke out into a brawl. With the Yankees leading 10–6 in the 7th inning, Yankees first basemen Tyler Austin got hit by a pitch thrown by reliever Joe Kelly. Austin was drilled with a 98 MPH fastball, possibly in retaliation after Austin slid foot-first into Red Sox shortstop Brock Holt in the 3rd inning, striking his leg and breaking up a double play. Holt questioned the slide and Austin briefly got in his face before the second base umpire David Rackley intervened. The benches emptied but it turned into a harmless stare down. The play was under review and was deemed a "bona fide slide" and did not break up the double play. Austin charged the mound and both teams benches and bullpens cleared with both Aaron Judge and Giancarlo Stanton helping to protect their teammates, as well as conducting damage control with Red Sox players. When the altercation settled down, Yankees third base coachPhil Nevin, who was "jawing" towards the Red Sox dugout, and Austin were ejected, along with Kelly. Also Yankees reliever Tommy Kahnle was tossed because he was "incensed" after he was pushed by an umpire in the scuffle. Discipline actions were set the next day: Kelly was fined and suspended for 6 games; Austin was fined and suspended for 5 games; while Nevin and Red Sox manager Alex Cora were issued undisclosed fines. Players on the Disabled List were also fined for entering the field during the skirmish: Yankees pitcher C.C. Sabathia and Red Sox infielders Xander Bogarts, Marco Hernández, and Dustin Pedroia.
May
The Yankees started the month winning against the Houston Astros 4–0 on a go-ahead 3-run home run by Gary Sanchez. They took over first place from the Boston Red Sox on May 9 by winning against them, 9–6. They finished the month going 17–7, putting them with a season record of 35-17. Even so, this set them back to second place in the division, 1 1/2 games behind the Red Sox.
June
The Yankees started the month with a 4–1 victory over the Baltimore Orioles. They finished the series with baseball's best record, even though they were still one game behind the Boston Red Sox for the division lead. This happened several more times throughout the month. On June 21, the Yankees made franchise history with a win over the Seattle Mariners, making it their 50th win on the season in just their 72nd game. In previous seasons, they reached that feat eight times. The Yankees finished the month losing 11–0 against the Red Sox. They went 18–9 for the month, putting their record at 53–27, one game back of the Red Sox.
July
The Yankees started the month by blowing out the Red Sox 11–1, putting them back into a tie for first place in the division. They hit 6 home runs in the game, setting the team record for the most home runs hit by a team before the All-Star break with 137. The Yankees sent four players to the All-Star Game in Washington, D.C.. Judge and Luis Severino played, while Torres and Aroldis Chapman sat out due to injuries. Before the Trade Deadline, the team acquired J. A. Happ from the Blue Jays, Zach Britton from the Orioles, Lance Lynn from the Twins, and Luke Voit from the Cardinals. The Yankees finished the month winning against the Orioles 6–3, going 15–10 for the month and 68–37 overall. This, however, pushed them 5 games back of the Red Sox, who continue to own the best record in baseball at 75–35.
August
The Yankees started the month losing to the Orioles 7–5 in the series finale. They traveled to Fenway Park to face the Boston Red Sox and tried to get closer to first place in the division. However they lost in a four-game sweep to their division rivals. The Yankees snapped their five-game losing streak with a 7–0 shoutout win over the Chicago White Sox, sweeping them in three games. At home, they then took three out of four from the Texas Rangers and lost the one-game matchup against the New York Mets 8–5, that was postponed previously due to weather inclements. The Yankees played the Baltimore Orioles in a four-game series spread out over three days, which saw the Yankees sweep the series and coming back to 6 games behind the Red Sox. The month ended with the Yankees winning against the Detroit Tigers 7–5, putting them 8 games back of the Red Sox.
September
The Yankees started the month winning 2–1 against the Detroit Tigers. Masahiro Tanaka completed back-to-back outings of 7 or more innings for the first time since September 2, 2017. The Boston Red Sox clinched the AL East title by winning against the Yankees 11–6 on September 20. However, the Yankees clinched an AL Wild Card spot two days later by winning against the Baltimore Orioles 3–2 in 11 innings. This will be the Yankees third postseason appearance in five years, all of which will begin with the Wild Card Game. On September 28, with a win over the Boston Red Sox, the Yankees clinched home field advantage and will face the Oakland Athletics in the AL Wild Card Game. The next day, with a 4th inning two-run home run by Gleyber Torres, the Yankees broke single season home run record set by the 1997 Seattle Mariners with 265 home runs. Also, the Yankees became the first team in MLB history to have at least 20 home runs from every spot in the batting order. As well as sharing history with the Red Sox. For the first season in MLB history both teams reached 100 wins.
October
The Yankees began the postseason by defeating the Athletics in the 2018 American League Wild Card Game 7-2. They moved on to face the Boston Red Sox in the ALDS. This was the first time since the 2004 American League Championship Series that the two teams faced each other in the postseason. They fell short in 4 games, as Boston defeated the Yankees 3 games to 1. This marks the first time in franchise history that they would lose in the postseason as a Wild Card team in back-to-back seasons.
