The Mavericks since Luka's injury have gone 1-5, and have gone from an offensive rating of 118.8 to 106.7, which would be a drop from the #4 offense to the #29 offense in the league
It seems that Luka Doncic was still a valuable basketball player in spite of many fans' assumptions. It remains to be seen if the Mavericks will be able to avoid the play-in spots through this rough stretch.
https://www.espn.com/nba/game/_/gameId/401705040
EDIT: I mean they have averaged 106.7 in this stretch for offensive rating, they have not fallen down to this