N/S Patrick Mahomes sr arrested for DUI in Texas

Not to speculate, but from his pictures he looks like he's lived a fast life. As an ex-MLB pitcher, he's seen his fair share of parties. As others have said, he probably needs serious rehab.
His complexion, face, worn, tired rugged stress and strain of playing in MLB for quite a few teams, over a decade or so added on to alcohol, drugs that were so prevalent and openly seen in American society from the late 70's-early 90's. You should do some research on the 1986 Pittsburgh MLB drug trials. Before many players began taking and abusing anabolic steroids in the late 1980's, this was probably the biggest "black eye" perspective on MLB, NFL, and NBA.

Mahomes Sr. looks like a man who's 10-15 years older then he really is.