Walton, 28, is a former third-round pick of the Broncos back in 2010. He spent three years with the team before be was waived and later claimed by the Redskins.
The Giants wound up signing him to a two-year, $5 million contract that included $3 million guaranteed back in March of last year, but he was released one year into the agreement.
San Diego elected to sign him to a contract over a month ago, but released him last week to make room for LB Joe Mays.
In 2014, Walton appeared in all 16 games for the Giants and was rated by Pro Football Focus rated as the No. 38 center out of 41 qualifying players last year.