Ja Morant will remain sidelined for the Memphis Grizzlies’ second preseason game against the Boston Celtics on Wednesday. The ultra-athletic point guard missed the team’s preseason opener against the Detroit Pistons on Monday after the Grizzlies received a concerning injury update on their superstar.Morant began training camp in high spirits and said all the right things, particularly when he voiced his desire to play all 82 regular-season games. However, that goal is now in serious jeopardy after he sustained a left ankle sprain during practice on Sunday. The two-time All-Star is considered "week-to-week," and there is currently no timeline for his return.Grizzlies coach Tuomas Iisalo addressed Morant’s injury and chose to focus on the positives rather than dwell on the immediate setback of not having his talisman available."Fortunately, we are only in preseason and we expect to have him back soon," the Grizzlies coach said.Ja Morant has struggled to stay on the court for the Grizzlies over the past two seasons as injuries have taken a serious toll on the superstar. The 6-foot-2 guard appeared in just 59 of the 164 regular-season games during that span.Meanwhile, Morant isn’t the only Grizzlies star currently dealing with an injury. Jaren Jackson Jr. is expected to miss at least four to six weeks, Zach Edey will be sidelined for six to nine weeks and Brandon Clarke is projected to miss around six weeks.How to watch Memphis Grizzlies vs. Boston Celtics preseason game?The Memphis Grizzlies vs. Boston Celtics preseason game will take place on Wednesday, Oct. 8, at the FedEx Forum in Memphis, Tennessee. Game will tip off at 8 p.m. EST (5 p.m. PT).The Grizzlies vs. Celtics game will be broadcast live on NBC Sports while live streaming will be available on the NBA League Pass and Fubo.