Dane Bo Henriksen has been appointed coach of relegation-threatened Mainz in succession of Jan Siewert on a contract until 2026, the Bundesliga club said on Tuesday. Henriksen, 49, joins Mainz from Switzerland’s Zurich, where he was in charge since 2022 but would not renew his contract beyond the season. He previously coached Danish sides including Midtjylland. His first match will be on Saturday against Augsburg, with the official presentation set for later Tuesday. Mainz head of sport Christian Heidel named Hedriksen “a coach that has managed to bring his teams together and get them to play …