LAKE FOREST, Ill.—Chicago Bears coach Matt Nagy has changed his mind and made Justin Fields the Chicago Bears’ starting quarterback going forward. On Monday, Nagy had said Fields was still the backup and playing only because of Andy Dalton’s knee injury. But on Tuesday he told both quarterbacks of the change and announced it Wednesday. Dalton will return to practice this week after suffering a bone bruise to his left knee and will be the backup. “I told you the last couple of weeks we’ve some good conversations internally,” Nagy said. “It’s helped us in the last couple weeks. “Continuing that process this week it’s led to making the decision to move with Justin as the starter.” Fields experienced a dreadful start, going 6 of 20 for 68 yards and taking nine sacks in Week 3 against Cleveland. In his first home start on Sunday he completed 11 of 17 …