McCants, 27, is a former sixth-round pick of the Giants back in 2012. He spent just over a year in New York before he was waived at the start of the 2013 season and later signed by the Raiders to their practice squad.
The Raiders used a low-round restricted tender on McCants several months ago that would have paid him $1,671,000 for the 2016 season. However, McCants agreed to a reduce his salary from $1.671 million to $675,000 at the start of the season.
McCants did, however, receive a $325,000 signing bonus, which brings his 2016 compensation to $1 million.
The Raiders cut McCants loose this past weekend.
In 2016, McCants has been limited to appearing in just two games for the Raiders.
Greco, 31, is a former third-round pick of the Rams back in 2008. After three years with the Rams, Greco signed on with the Browns and has spent the past six years in Cleveland.
Greco is currently in the fourth year of his five-year, $13.2 million contract and stands to make a base salary of $925,000 for the 2016 season.
This year, Greco appeared in 12 games for the Browns and is rated by Pro Football Focus as the No. 19 guard out of 81 qualifying players.