Chicago Bears 2020 training camp check-in: Defensive Line

How has the Chicago Bears defensive line looked in training camp so far?
One month ago the Chicago Bears defensive line was the biggest strength. Today, there are more questions. The starting four were set to be Robert Quinn, Eddie Goldman, Akiem Hicks, and Khalil Mack.
Since then, Goldman has opted out. Robert Quinn has yet to practice and Akiem Hicks has missed the last two days with an injury. All of a sudden Khalil Mack looks like the Will Smith gif wondering where everybody went.
The Bears have noted that they are not concerned about Quinn. He is not listed as out with any injury. They just do not want to waste the athleticism of an aging veteran who has had injuries in his past. They also trust that his role is not the most complex, as he will line up and rush the passer, something he has done for years.
Hicks is a bit worrisome. He is 30 years old now, which is the age where players start to lose that top-end notch. Other players could hit an injury wall. Hicks obviously is coming off of an injury, so even though the two are unrelated it is worth monitoring as he gears up for the season.
Could the Bears just be cautious right now as they know what they have in Hicks? Certainly, but seeing quad next to his name has to raise some eyebrows nonetheless. Here is to hoping he is fine.
Goldman will not be back, but all indications are that Bilal Nichols is more than capable of filling in. He has been off of the charts and is in for a big year.
Next. Bilal Nichols career trajectory. dark
Trevis Gipson has taken advantage of the Quinn absence but is still behind Barkevious Mingo, and others on the depth chart.