Sammy Lee began work back at Liverpool this morning.
The 49-year-old's appointment comes following the departures of former Assistant Manager Pako Ayesteran at the start of last season, and first team coach Alex Miller, who took up a management role in Japan earlier this month.
"We are very pleased to have brought Sammy back to Liverpool because he is someone who knows the club really well," said Benitez.
"He also knows about the passion of the club and about the standards that we set here so that will make it much easier for him to settle into his new role.
"But we have not brought Sammy back simply because he used to play for the club and used to work here as a coach.
"He is a very experienced and very well respected coach in his own right and his reputation in football made him the stand out candidate when we knew we were looking for a new member of our coaching staff.
"He will add something different to what we already have and it will be good to work with him.
"I already have a good relationship with him and I will be looking to build on that in the weeks and months to come."