Despite a career wRC+ of only 81 he's managed to be worth a little bit of positive WAR every year since 2015.
https://www.fangraphs.com/players/jake-marisnick/11339/stats?position=OF
Down 4-1, Boone left him in, with 2 runners on base, to face Kimbrel in the 9th last night while Rizzo sat restlessly on the bench. JD popped out, game over.