By Alek Arend The jump from year one to two can often be significant for NFL quarterbacks. Could Justin Fields be next in line? Fields struggled during his rookie season. Some of that can be attributed to the mess Matt Nagy created. However, he’s not entirely at fault. The former Ohio State star had plenty of ups and downs. He finished the year with 1,870 yards and seven touchdowns with 10 picks. He added 420 yards and two additional scores on the ground. The Bears went 2-8 as the starter. How has Fields improved as a quarterback since then? Khalil Herbert told reporters on Tuesday that the fo…