The Infinity Stones have played a large role in the MCU over the past decade, so it’s safe to say that they will play a major role in Avengers 4, just like they did in Infinity War. The Avengers could end up going back to Nidavellir to use the old mold of the Infinity Gauntlet that was seen during Infinity War to handle the 6 stones on their own.
For those of you who have not seen Avengers: Infinity War yet, there are major SPOILERS below, so read ahead at your own risk.
The visual of the scarecrow is taken from the Infinity War comic in what is known as Farmer Thanos to Marvel fans.
Infinity War does not expressly say exactly what happened to the Infinity Stones or the Gauntlet, but it sure does imply that it has been badly damaged.