Lockhart has been out of action after two concussions in a two-week period. The second came after a hard foul in the second half of the game against Arkansas State in Jonesboro.
Shields said: "Still having some headaches in the mornings and [UALR Athletic Trainer Michael Switlik is] working with him daily. Not real sure if we'll get him back this year. Anytime you're dealing with those head injuries it's a touchy deal. With the NFL and all the concussions and the way that's played out, you've got to make sure before you bring those guys back."
Time is running out for Lockhart to return. UALR begins Sun Belt Tournament play at 6 p.m. on Saturday against Florida International.
Lockhart is averaging 5.1 points, 2.7 rebounds and 1.3 assists in 20.7 minutes this season. Even missing as many games as he has, Lockhart ranks third on the team in plus/minus for Sun Belt Conference games.