Maxwell has a cap hit of $9.7 million for 2016, which the Dolphins are expected to try to restructure. Miami would save $6.5 million in cap space by parting with Grimes.
The Eagles traded the two players to the Dolphins for a draft choice, a person familiar with the deal said Monday. The person confirmed the trade to The Associated Press on condition of anonymity because it won't be announced until Wednesday, the first day of free agency.

The Dolphins are looking to upgrade defensively under new coach Adam Gase after ranking 25th last season in yards allowed. They're also in the market for help at defensive end and safety.
As a rookie Alonso had 87 tackles, four interceptions,Jerseys NFL Wholesale, two sacks and two fumble recoveries for the Bills. He sat out the 2014 season after tearing his ACL, and hurt the same knee again last year.
Maxwell is going into the second year of a $63 million, six-year contract he received after starting only 17 games in four seasons with Seattle. He had two interceptions in 14 games for the Eagles, who ranked 28th in pass defense.
The deal is pending physicals, and Alonso has knee issues.
MIAMI (AP) — Cornerback Byron Maxwell and linebacker Kiko Alonso will try to accomplish for the Miami Dolphins what they failed to do in Philadelphia — upgrade the defense.
Alonso had also played for Kelly at Oregon,Wholesale Jerseys From China.
Maxwell and Alonso both had a disappointing year in Philadelphia after they were acquired before the 2015 season by coach Chip Kelly, who was fired before the season finale. Philadelphia finished 7-9.
Alonso,Cheap Jerseys, a second-round draft pick by Buffalo in 2013,Cheap Nike Air Max 90 Mens Trainers, has battled injuries and started only one game last season. He was acquired by Philadelphia in a trade for two-time All-Pro running back LeSean McCoy.
The Dolphins' acquisition of Maxwell may mean they plan to part with four-time Pro Bowl cornerback Brent Grimes. He became expendable because of a decline in his play last season and issues involving his wife, Miko,NFL Jerseys China, who was arrested at the stadium before a game and ripped Miami quarterback Ryan Tannehill on Twitter.