(SportsNetwork.com) - It appears as if the San Francisco 49ers will stay in- house for Jim Harbaugh's successor.

Multiple reports on Wednesday said that the 49ers will elevate longtime defensive line coach Jim Tomsula to become the team's new head coach.

ESPN.com first reported the news, which NFL.com later confirmed through sources involved in the process.

Tomsula has been a Niners assistant since 2007 and worked under three head coaches -- Harbaugh, Mike Nolan and Mike Singletary -- over that stretch. He also served as the team's interim head coach for the 2010 season finale after Singletary was fired.

The 46-year-old takes over a San Francisco squad that reached the NFC Championship Game in three straight seasons under Harbaugh from 2011-13, but is presently in a state of transition following Harbaugh's recent departure to become the head coach at the University of Michigan.

With rumors of friction between Harbaugh and the 49ers' front office swirling all throughout this past season, San Francisco dropped four of its final four games after a 7-4 start to miss out on the playoffs.

There were other off-field distractions the Niners had to deal with as well. Top pass rusher Aldon Smith was suspended for the first nine games for multiple violations of the NFL's personal conduct policy, while defensive lineman Ray McDonald was released in December after being investigated for an allegation of sexual assault.

Tomsula may be having to find two new coordinators during the offseason. Offensive play-caller Greg Roman accepted the same position with the Buffalo Bills earlier in the week, while it is unclear whether defensive coordinator Vic Fangio will return after being passed over for Tomsula for the head coaching nod.

The 49ers also had discussions with two-time Super Bowl champion head coach Mike Shanahan as well as Denver Broncos offensive coordinator Adam Gase before deciding on Tomsula.