Alex Karras, one of the most dominating players of his generation and considered a Detroit Lions great, is in a critical condition following a kidney failure.

Karras is 77.

His condition has been deteriorating since last week. He was also a Hollywood actor.

The American Football fraternity and the Lions team members, coaches and managers were extremely saddened by the news.

''The entire Detroit Lions family is deeply saddened to learn of the news regarding the condition of one of our all-time greats, Alex Karras. Perhaps no player in Lions history attained as much success and notoriety for what he did after his playing days as did Alex," the Associated Press quoted Tom Lewand, the Lions' president, as saying.

Karras was considered one of the most active players during his playing days and is still remembered for his flawless defense.

He further added, ''We know Alex first and foremost as one of the cornerstones to our Fearsome Foursome defensive line of the 1960s and also as one of the greatest defensive linemen to ever play in the NFL. Many others across the country came to know Alex as an accomplished actor and as an announcer during the early years of 'Monday Night Football.' We join his legions of fans from both sports and entertainment in prayer and support for Alex, his wife Susan, and his entire family during this most difficult time.''

Karras, also nicknamed "The Mad Duck," played football with the Detroit Lions in the National Football League from 1958-1962 and 1964-1970. He is noted as an actor for his role as the thuggish Mongo in the 1974 comedy film "Blazing Saddles", and also for starring in the ABC sitcom "Webster" (1983-87), alongside real-life wife Susan Clark, as the titular character's adoptive father.

Alex Karras was drafted in the first round of the NFL draft by the Detroit Lions in 1958. He quickly became one of the dominant defensive tackles in the NFL. He retired at 35, playing for the Lions throughout his career.

Karras sued the NFL, as did many other retired players, for their negligence in treating head injuries that players sustained in their games. Karras's wife recently revealed that the head injuries he had sustained during his playing career with the Lions adversely affected his day-to-day life.

She said, "This physical beating that he took as a football player has impacted his life, and therefore it has impacted his family life. He is interested in making the game of football safer and hoping that other families of retired players will have a healthier and happier retirement.''

Meanwhile, the NFL has confirmed that it has taken appropriate measures to protect players from injuries and that it had never intended to mislead them.