The Dallas Mavericks ruled out star Luka Doncic (left thigh strain) for Monday night’s game against the Memphis Grizzlies, with Kyrie Irving (sore right foot) and Tim Hardaway Jr. (non-COVID illness) questionable for the contest.The matchup is key for both teams as they seek to cement their playoff positioning in the Western Conference.The Grizzlies are battling the Sacramento Kings for second place in the West with an outside hope of chasing down the current top seed, the Denver Nuggets, who have a four-game lead. Meanwhile, the Mavericks (36-35) are holding on to the final guaranteed playoff spot in the conference, a half-game ahead of the seventh-seeded Golden State Warriors.Doncic leads the Mavericks with averages of 33.0 points, 8.6 rebounds, 8.0 assists and 1.5 steals per game over 57 contests.