Castonzo, 29, is a former first-round pick of the Colts back in 2011. He’s currently in the fourth year of his five-year, $49.438 million contract that includes $18 million guaranteed and stands to make base salaries of $6 million and $6.25 million over the next two years.
In 2017, Castonzo appeared in all 16 games for the Colts.
Howard, 31, originally signed on with the Eagles as an undrafted free agent back in 2010. He had a brief stint with the Ravens before he was signed to the Jets’ active roster in 2011.
After three years in New York, Howard signed a five-year, $30 million contract that included $15 million guaranteed with the Raiders but was cut loose last year. The Ravens signed Howard to a three-year, $15.02 million contract a few months later before declining his option this offseason.
The Colts later signed Howard to a contract.
In 2017, Howard appeared in all 16 games for the Ravens and is rated by Pro Football Focus as the No. 36 offensive tackle out of 81 qualifying players.