Brian Hartline has described teammate Ryan Tannehill's improvement during the off-season as "amazing".
The Miami Dolphins quarterback is preparing for his second season in the NFL, having led the side to a second-placed finish in the AFC East last season.
The wide receiver told the Palm Beach Post: "He's making every throw, his deep ball looks awesome, and he's got great touch.
"You don't feel like it's a rocket coming into your hands. His improvement has been amazing."
Tannehill completed 3,294 passing yards in his rookie season.
