Also given full clearance were running backs Ronnie Brown and Patrick Cobbs, quarterback Chad Pennington and cornerback Will Allen, all returning from operations necessitated by season-ending injuries in 2009.
Shortly before the first practice Friday, coach Tony Sparano said his team is at full health.
The Dolphins acquired Marshall from Denver in a trade in April, and he underwent hip surgery in May.
Brown missed the final seven games last year because of a foot injury. Pennington lost his starting job when he was hurt in the third game in 2009, and he'll compete for the No. 2 job behind Chad Henne.
Meanwhile, defensive end Charles Grant signed with the team on Friday. Grant spent his entire career with the New Orleans Saints before joining the Dolphins for the start of training camp. He started all 16 games for the Saints last season and had 5½ sacks.
Information from The Associated Press was used in this report.