Borussia Mönchengladbach stalwart Tony Jantschke is following team mate Patrick Herrmann and retiring at the end of the season. The 34-year-old defender has played for 16 years with Gladbach, his only professional team. “Full of pride, I announce that my Borussia journey as a player will end in the summer,” he said on Instagram on Tuesday. But he looks set to stay at the mid-table Bundesliga side “as part of the coaching team to look after our top talent in the professional squad and the youth training centre,” sporting director Roland Virkus added in a statement. Jantschke has racked up 301 c…