De Boer was alongside Van Marwijk on the bench during Wednesday night's 1-1 friendly draw with Russia, and the coach on Friday confirmed the former Ajax and Barcelona defender will become a permanent member of his staff.

While three other members of Van Marwijk's technical staff, Dick Voorn, Phillip Cocu and Ruud Hesp watch games from the stands and keep in touch via headsets, Van Marwijk wants De Boer to stay alongside him in the dugout.

"Although we have known each other only a short time, I've clicked very well with Frank," Van Marwijk said in AD Sportwereld. "When it comes to how we think about football, we are on the same wavelength."