Former captain Wijnaldum, 33, moved to Al Ettifaq in Saudi Arabia this season and earns a first call-up since the Nations League finals in June last year. Memphis, 30, has had an injury-hit last 12 months and has not played for the national team since March last year.
Both are stalwarts of the side though and while Memphis was always likely to be called when fit, Wijnaldum's return could be with an eye on adding experience ahead of the Euros in Germany.
Timber, 22, is the twin brother of Arsenal defender Jurrien, who is also a Dutch international but has not been selected for the home game against the Scots in Amsterdam on March 23 and the away trip to Frankfurt in Germany three days later.
Netherlands squad:
Goalkeepers: Marco Bizot (Stade Brest), Mark Flekken (Brentford), Bart Verbruggen (Brighton & Hove Albion)
Defenders: Nathan Ake (Manchester City), Daley Blind (Girona), Virgil van Dijk (Liverpool), Denzel Dumfries (Inter Milan), Jeremie Frimpong (Bayer Leverkusen), Lutsharel Geertruida (Feyenoord), Quilindschy Hartman (Feyenoord), Matthijs de Ligt (Bayern Munich), Stefan de Vrij (Inter Milan)
Midfielders: Teun Koopmeiners (Atalanta), Tijjani Reijnders (AC Milan), Marten de Roon (Atalanta), Jerdy Schouten (PSV), Xavi Simons (RB Leipzig), Quinten Timber (Feyenoord), Joey Veerman (PSV), Mats Wieffer (Feyenoord), Georginio Wijnaldum (Al-Ettifaq)
Forwards: Brian Brobbey (Ajax), Memphis Depay (Atletico Madrid), Cody Gakpo (Liverpool), Donyell Malen (Borussia Dortmund), Wout Weghorst (Hoffenheim).
