10:49 AM PT -- Gosder Cherilus is blaming sleeping meds for the incident ... saying in a statement on Monday, "In preparation for the unexpected overnight flight, I took a sleeping medication that I don't normally use, which resulted in behavior that is not representative of my character."

The former first-round pick went on to issue an apology to the passengers and the crew aboard the plane.

Former NFL offensive lineman Gosder Cherilus -- the 17th overall pick in the 2008 NFL Draft -- was arrested over the weekend ... after he was accused of peeing on a passenger while aboard an airplane.

Massachusetts State Police say the incident occurred on Sunday morning ... while the former footballer was on a Delta flight bound from Boston to Ireland.

Cops say Cherilus was "unruly" while on the plane -- and when officers arrived at Logan Airport at around 2 AM and demanded he get off the plane after it landed, they say he "became irate and uncooperative."

Ultimately, police say 40-year-old Cherilus was hauled off the plane, arrested, and booked on charges of disorderly conduct and disturbing a flight crew.

He's reportedly due to be arraigned in court on Monday.

After being picked by the Lions in 2008, Cherilus -- a star at Boston College -- went on to play nine seasons in the NFL. He logged snaps with Detroit, Indianapolis and Tampa Bay ... and earned 116 total starts in his career. He announced his retirement in March 2017.