Celebrates his 41st birthday on the day of The Open’s first round, having earned a return to the Championship on Sunday by winning the European Challenge Tour’s Le Vaudreuil Challenge.
He last played at The Open in 2015, a year after his best major finish of joint 12th in the U.S. Open.
Siem is a four-time winner on the European Tour, although there was an eight-year gap between his maiden title at the 2004 Alfred Dunhill Championship in South Africa and the 2012 French Open, where he beat Francesco Molinari by one.
In between partnered Bernhard Langer as Germany won the World Cup following a play-off with Scots Colin Montgomerie and Marc Warren, then added the 2013 Hassan Trophy and 2014 BMW Masters.
He reached a high of 48th in the world in 2013, but a year ago he was not even in the leading 1,000.
Siem represented his country in the 1998 and 2000 World Amateur Team Championship and also played for Europe against Asia in the 2012 Royal Trophy.