If by the trade deadline, the pacers haven't turned the corner and started winning consistently then we need to trade Foster.
Look I know alot of people love Foster, I love him too. But I love the Pacers more. This teams needs a defender, somebody who can lock down the paint, guard the opposing teams best PF/C. We all know Foster has value. Any team would love to have his production and contract. So you could literally set up any number of deals that include foster and an expiring like Daniels or Rasho.
Additionally we've already seen in limited minutes McRoberts is way more athletic, and in my opinion potential to be a better defender. He can be a gritty energy player in the same vein as Foster is now. He only needs to get fouls under control. Better trade Foster now while he has value. Cause he is clearly going to decline in production over the next several years. It makes no sense to hold on to a player who will continually get worse.
So if this team hasn't developed by the trade deadline, which really would be a good bench mark anyway because we are just staring to get healthy again. Then its time to cash in some value. Start developing McRoberts to be Foster 2.0, and go get that defensive stopper.