Sammy Lee has joined Bolton for a third time during his football career.
The 53-year-old, who finished his playing days with the club in 1991 and was assistant manager and then manager from 2005-07, has now taken up the role of head of academy coaching.
Lee has been out of work since leaving Liverpool last summer after Kenny Dalglish decided to reorganise his backroom team.
Bolton boss Owen Coyle believes Lee will prove a valuable addition to the club.
"I know Sammy will bring a great deal of top-level coaching experience and enthusiasm, and that can only be of huge benefit for our youth players," said Coyle.
Meanwhile, young midfielder Josh Vela has signed a three-and-a-half-year contract extension.
The 18-year-old stood on the brink of a first-team breakthrough earlier this season until fracturing a foot in a reserve game in November.
Vela has now returned to fitness and he has set his sights on breaking into the first-team.
"It's been a bit of a frustrating season for me with the injury, so I just want to continue working hard," Vela told the club's official website.
"My aim is of course to get into the first team, and I know I've still got a lot to learn, but I feel I am developing into a better player as each day goes by."