On May 8, 2018, Heyward again went on the disabled list due to concussion protocols after attempting a game-saving catch of a hit by Dexter Fowler in the 14th i14th-inningruninning.<ref>{{Cite web |last=Muskat |first=Carrie |date=May 18, 2018 |title=Cubs place Heyward on concussion DL |url=https://www.mlb.com/cubs/news/jason-heyward-injured-placed-on-concussion-dl/c-275828400 |access-date=July 16, 2018 |website=MLB.com}}</ref> On June 6, Heyward hit a walk-off grand slam home run with two outs in the bottom of the ninth inning to give the Cubs a 7–5 win over the [[Philadelphia Phillies]].<ref>{{Cite web |date=June 6, 2018 |title=Heyward's walk-off grand slam |url=https://www.mlb.com/video/heywards-walk-off-grand-slam/c-2126932683 |access-date=July 16, 2018 |website=MLB.com}}</ref> At the All-Star break, Heyward had a .285 batting average with 78 hits in 274 plate appearances with six home runs and 41 RBIs, a .344 OBP and a .431 SLG.<ref>{{Cite web |title=Jason Heyward 2018 Batting Game Logs |url=https://www.baseball-reference.com/players/gl.fcgi?id=heywaja01&t=b&year=2018 |access-date=July 13, 2021 |website=Baseball-Reference.com |language=en}}</ref> Heyward ended the season with a .270 batting average, eight home runs, and 57 RBIs.<ref name="mlbstats" />
