The 34-year-old veteran, an All-Star in 2011, is a son of Detroit Tigers general manager Al Avila. He has played in the majors for parts of 13 seasons, and is hitting .179 with seven RBIs this year.
Avila said he expects to continue in baseball next season in a non-playing role. He said he has not spoken with his father about a position. Al Avila once traded his son.
Drafted by the Tigers in the fifth round back in 2008, Avila played eight seasons with Detroit. In that All-Star season for Detroit, he hit 19 home runs and finished with a .295 batting average.
"I always figured I would know when I feel like I've given everything I possibly can physically on the field," he said. "And at that point, I would call it an end."
Avila joined the Nationals this season, agreeing to a one-year deal at a price tag of $1.4 million.
The Associated Press contributed to this report.