Martini went 3-for-4 with a double, a walk and two RBI in Saturday's 8-7 win over Arizona.
Martini has now posted a monstrous 1.423 OPS through five games with the Reds since being called up from Triple-A Louisville on Tuesday, and so long as he's wielding a hot bat, he'll likely continue to play on a near-everyday basis while Cincinnati is without the likes of Jonathan India (foot), Joey Votto (shoulder), Jake Fraley (toe) and Stuart Fairchild (concussion). Martini will serve as the Reds' designated hitter and No. 5 batter in Sunday's series finale.