Cobb, 23, is a former fifth-round pick of the Titans last year. He was in the second year of his four-year, $2,252,668 rookie contract and set to make a base salary of $525,000 for the 2016 season when he was cut by the Titans in the final week of the preseason.
The Steelers later signed him to their practice squad at the start of the season only to cut him loose last week.
In 2015, Cobb appeared in seven games for the Titans and ran for 146 yards on 52 carries (2.8 YPC) to go along with one reception for -2 yards receiving and a single touchdown.
Weems, 28, originally signed on with the Vikings as an undrafted free agent out of Oregon back in 2012. Since then, he’s played for the Buccaneers, Colts and Patriots before joining the Cowboys in December of 2012.
Weems was unable to make the 53-man roster coming out of the preseason, but was later added to the team’s practice squad soon after. The Broncos signed him to a future/reserve contract this past January only to place him on waivers Monday to make room for OL Billy Turner, who has been claimed off of waivers from the Ravens.
This season, Weems has appeared in six games for the Broncos.