Mainz have signed Norwegian defender Andreas Hanche-Olsen from Belgian side Gent, the Bundesliga club said on Friday. The player signed a “long-term deal,” the club said without giving further details. “We have been watching Andreas Hanche-Olsen for quite some time. We already made serious considerations about him in the summer, so it’s even nicer that we have managed to finalize the transfer in January,” Mainz sporting director Martin Schmidt said. The defender made 107 appearances for Gent since arriving at the club in 2020 and featured 21 times in the Europa League and Conference League. “I…