Of the three, the release of Terrell would have been considered the biggest surprise following the draft, as Terrell was one of the the highest-rated rookie free agents left available. As OBR football analyst Lane Adkins has been reporting, however, Terrell has struggled during OTAs and the team's mandatory mini-camp, while unheralded CB Mil'von James has looked promising.
WR Nate Hughes was also released. Hughes has looked solid during this summer's practices, so his release displays the team's confidence in the other receivers on the depth chart. The resurgence of WR Travis Wilson and the solid camp performance of veteran WR Kevin Kasper are likely factors here.
The releases make room for rookie contract signings, and also allowed the team to pick up Miami Hurricane OG Derrick Morse, who attended the team's rookie tryouts in April. Morse is 6'4", 325 and recorded middling numbers during workouts. While his numbers aren't impressive, Morse is a plugger who was solid for Miami throughout his career.
Adding Morse presumably gives the Browns more training camp bodies at offensive guard, where the team has had to deal with the injury to RG Ryan Tucker and the release of LeCharles Bentley. Last year's starting RG, Seth McKinney, has been working largely as a backup center, which made the Browns thin at the position during mini-camp.