The 54-year-old, who has signed a contract until summer 2022, arrives from Hannover 96, where he previously worked under his fellow German.

Hearts sit bottom with the Scottish Premiership now in its winter break.

"We have a little bit of time now before the next game and we have work to do," Sievers told Hearts' website.

Sievers spent 10 years as a player at Hannover 96, now in Germany's second tier, and played more than 350 games for the club before retiring to take over as goalkeeper coach in 2003.

"When Daniel was the manager, I was his assistant, so I know him well," said Sievers, who stressed he is "fully aware" of Hearts' precarious position in the Scottish top flight.

"He got in touch with me and asked me to join him here at Hearts. I travelled over to Edinburgh for a few days last month and was able to watch the games against Hibs and Aberdeen at Tynecastle.

"During that time, I was able to visit the training centre as well and everything felt very good, so I said yes."

Hearts, who are five points behind Hamilton Academical, are yet to record a victory in five games since Stendel took over from caretaker manager Austin MacPhee.

Andy Kirk has been assisting with coaching duties, but the new manager was keen to bring in his own coaches who know about the style of play required, with Stendel favouring a high-pressing tactic.

Sievers had returned to his role as goalkeeping coach at Hannover following Stendel's move to Barnsley.