Rosenior will take his first steps into coaching assisting Simon Rusk ahead of the under-23s’ Premier League 2 Division 1 campaign, in the role of professional development phase coach.
Albion chief executive Paul Barber said, “We are delighted to welcome Liam back to the club in a coaching capacity.
“He was a hugely popular figure in the dressing room during his playing days here, and we are very pleased to give him the platform to begin his coaching career.
“Liam had always shown a very active interest in coaching since his arrival at the club, and impressed the academy coaching staff with his knowledge and expertise when taking sessions with the younger players.
“His role as an Albion in the Community ambassador was also very successful, and this job will enable him to maintain close links with the club’s charity.
“We recognise how important it is to have characters like Liam in and around the club, and I am sure he will seamlessly adapt to his new role.”
Rosenior arrived at the club on a free transfer in June 2015, following the end of his contract at Hull City.
He made 31 appearances during his first full season at the club as the side narrowly missed out on automatic promotion.
The full-back missed out on a chunk of the 2016/17 promotion-winning campaign with an ankle injury, but returned for the second half of the season as Albion reached the Premier League.
Game time was limited for the defender last season, making his final appearance in the 2-1 defeat AFC Bournemouth in September.
The defender also featured Reading, Fulham, Ipswich Town, Bristol City and Torquay United in a lengthy playing career, and also represented England up to under-21 level.