Wales defender Jazz Richards has signed for Cardiff City from Fulham on a three-year deal, with Bluebirds left-back Scott Malone moving the other way.
Malone, 25, played 42 times for Cardiff last season and has signed a two-year contract with Fulham.
Richards, 25, was part of Wales' squad at Euro 2016, making one substitute appearance, with new Cardiff boss Paul Trollope on the national coaching team.
"We think he'll be a great addition to the squad," said Trollope.
He joined Fulham in January 2015, having played more than 50 games for Swansea City.
Former Wales and Cardiff defender Danny Gabbidon thinks the move to the Bluebirds will suit Richards.
"I think it could be a good move all round. If anything at the minute, Jazz is probably playing better for his country than his club," he told BBC Radio Wales Sport.
"Obviously he's worked with Paul Trollope in the Welsh set-up, that would help him. I think he needs to play week, in week out."
Malone scored two goals in 56 appearances for Cardiff since joining from Millwall in January 2015.
The 25-year-old was not in the Bluebirds' squad for their 4-0 pre-season friendly win at Shrewsbury on Saturday as the move to Fulham was being finalised.
Cardiff impressed in their new 5-3-2 formation, which Wales used to excellent effect in their historic run to the Euro 2016 semi-finals.
Richards featured prominently in that system during Wales' qualification campaign, and new Bluebirds head coach Trollope hopes his arrival will be one of many at Cardiff City Stadium.
"I think there's a few to come," added Trollope. "We are actively looking to strengthen. I think the group is a good group, there's a good core here."