"I did see a transformation in leadership -- Jay, Josh, I saw Brandon Marshall take big steps," Emery said. "I saw the leadership transfer on defense to Lance Briggs ... and when he was hurt he continued that leadership role, fully involved himself."
Emery said the loss of cornerback Charles Tillman, who can become a free agent, was a major setback.
"He's a physical, playmaking football player," Emery said of Tillman. "His loss has a significant impact on where we were as a defense."
Emery spoke highly of Cutler on many occasions before the signing was made official Thursday. His heavy praise of Tillman could imply the Bears are planning to work out a contract with the veteran, or use the franchise tag to retain him.
Of the areas of concern entering 2014, the general manager focused on defensive improvement.
"We had a lot of tough days defensively -- a tough season," Emery said. "There are no excuses for it.
"All aspects are on the table to be evaluated. We want a physical, fast, playmaking defense. A defense that causes disruption. I saw that in the first three games."
Trestman said "everything is on the table three days into a through process" regarding defensive coordinator Mel Tucker.
Emery said the defense will be younger in 2014, and a focus of the team's draft plans.
--Tucker is involved in parts of the team review, according to Trestman, who hinted that 2012 first-round pick Shea McClellin and 2013 second-round pick Jon Bostic might be better fits at outside linebacker. McClellin was drafted as a pass-rush specialist, Emery said. Trestman said the switch is just one possibility, as is moving to a 3-4 front.
--Regarding the free agent status of injured defensive tackle Henry Melton, who drew the Bears' franchise tag in 2013 before suffering a season-ending injury, Emery said "He needs to make sure that he's focused in on football and having a passion for football."
--Melton is one of several potential free agent defensive linemen. Emery said Corey Wootton will be extremely popular if he reaches the open market because his skill set "transcends scheme." Wootton played defensive end and defensive tackle to the Bears and could easily transition to a 3-4 defense. Jeremiah Ratliff, who came on late in the season, is a candidate to return if he's interested.