What happened to Adam Ruzek's dad on Chicago PD?

Adam Ruzek (Patrick John Flueger) is having a crisis of confidence. The Chicago PD veteran went through a harrowing incident in season 10 when he was shot in the stomach, and the first episode of season 11 proved that he isn't quite yet ready to get back to work.

Ruzek has undergone six months of physical therapy, and is healthy enough to go on runs, but he hasn't been able to pass the power test, which is necessary for him to be cleared for duty. We got an inkling of his frustration in the season 11 premiere, but the second episode of the season will narrow the focus to him and his struggles.

Ruzek struggles with his dad's legacy in season 12

The synopsis for season 11 episode 2, titled "Retread", reads as follows:

"Ruzek gets mixed up in a case after a late-night poker game is raided; afraid of becoming like his father, Ruzek struggles to stand down and allow Intelligence to carry out the investigation while he remains on leave."

The mention of Ruzek's father may be puzzling for some, and for good reason. Ruzek's dad, Robert "Bob" Ruzek (Jack Coleman), hasn't appeared on the show since season 8, and has only appeared in three episodes total. This is why a refresher on his story might be useful.

Related: Chicago PD promises more Burzek storylines

Bob Ruzek was also a member of the Chicago police department, but unlike his son, he was willing to cut corners and cover things up if it meant securing an arrest. This put him at odds with Hank Voight (Jason Beghe), and created a rift between him and his son as the latter got older.

The two men had a falling out in season 8

In the season 6 episode "Fathers and Sons", Ruzek discovers that his dad is working for a suspect in a criminal case. Eventually, the elder police officer reveals that he is broke and working extra (illicit) jobs for money. Ruzek agrees to help his dad out, but things sour by the time season 8 rolls around.

In the season 8 episode, its revealed that Bob Ruzek is selling information about police informants to local gang members for money. The younger Ruzek confronts him about him, and he comes clean, but the incident damages what's left of their relationship. The two officers have not been seen together since.

Bob Ruzek also retired from the police department in season 8. While its unlikely that he will appear in season 12, the fact that Ruzek is struggling on the job, and worried that he will turn out to be more like him than he expected, means that character is incredibly important to understanding the show.