Question: Michael Anthony Williams costarred with what real-life boxer in Rocky V?

Context paragraphs:
Rocky V: Rocky V is a 1990 American sports drama film.  It is the fifth film in the "Rocky" series, written by and starring Sylvester Stallone, and co-starring Talia Shire, Stallone's real-life son Sage, and real-life boxer Tommy Morrison, with Morrison in the role of Tommy Gunn, a talented yet raw boxer.  Sage played Robert Balboa, whose relationship with his famous father is explored.  After Stallone directed the second through fourth films in the series, "Rocky V" saw the return of John G. Avildsen, whose direction of "Rocky" won him an Academy Award for Best Directing.

Rocky (film series): Rocky is a series of boxing films based on the eponymous, fictional character Rocky Balboa, played in each film by Sylvester Stallone.  The films by order of release date are: "Rocky" (1976), "Rocky II" (1979), "Rocky III" (1982), "Rocky IV" (1985), "Rocky V" (1990), "Rocky Balboa" (2006) and "Creed" (2015).  The film series has grossed more than $1.4 billion at the worldwide box office.

Mike Williams (boxer): Michael Anthony Williams (born June 16, 1962) is an American actor and former professional boxer who competed from 1984 to 2000.  He is most notable for portraying fictional boxer Union Cane in the 1990 film "Rocky V".

List of Rocky characters: This is a list of characters from the "Rocky" film series, consisting of "Rocky" (1976), "Rocky II" (1979), "Rocky III" (1982), "Rocky IV" (1985), "Rocky V" (1990), "Rocky Balboa" (2006), and "Creed" (2015).

Tommy Morrison: Tommy David Morrison (January 2, 1969 – September 1, 2013) was an American professional boxer who competed from 1988 to 1996, and held the WBO heavyweight title in 1993.  He retired from boxing in 1996 when he tested positive for HIV, but returned for two more fights in 2007 and 2008.  Morrison is also known for starring alongside Sylvester Stallone in the 1990 film "Rocky V".

Michael Anthony (musician): Michael Anthony Sobolewski (born June 20, 1954 and legally shortened his name to Michael Anthony in 1978), is an American musician who is currently the bass player in the rock supergroup Chickenfoot and the Circle.  Anthony is best known as the former bass player for the hard rock band Van Halen.

Dick Anthony Williams: Dick Anthony Williams (born Richard Anthony Williams; August 9, 1934 – February 16, 2012) was an American actor.  Williams is known for his starring performances on Broadway in "The Poison Tree", "What the Wine-Sellers Buy" and "Black Picture Show".  Williams won the 1974 Drama Desk Award for his performance in "What the Wine-Sellers Buy", for which he was also nominated for a Tony Award, and was nominated in 1975 for both a Tony and a Drama Desk Award for his performance in "Black Picture Show".

John G. Avildsen: John Guilbert Avildsen (December 21, 1935 – June 16, 2017) was an American film director.  He won the Academy Award for Best Director in 1977 for "Rocky".  Other films he directed include "Joe" (1970), "Save the Tiger" (1973), "Fore Play" (1975), "The Formula" (1980), "Neighbors" (1981), "For Keeps" (1988), "Lean on Me" (1989), "Rocky V" (1990), "The Power of One" (1992), "8 Seconds" (1994), "Inferno" (1999) and the first three "The Karate Kid" films.

Mike Williams (American football, born 1957): Michael Anthony Williams (October 14, 1957 – December 23, 2013) was an American football player who played three seasons with the Kansas City Chiefs of the National Football League (NFL).  He was drafted by the Chiefs in the eighth round of the 1979 NFL Draft.  He played college football at the University of New Mexico and attended Parkland High School in El Paso, Texas.  Williams died of heart failure on December 23, 2013 in El Paso, Texas.

Rocky V (album): Rocky V: Music From and Inspired By the Motion Picture is the soundtrack album to the 1990 film "Rocky V".

Supporting paragraphs: Mike Williams (boxer) Rocky V
Answer: Tommy Morrison