Mattingly took over for as manager for Los Angeles in 2011, leading them to a 260-225 record (.563 winning percentage). They won the NL West pennant last season, and came within two games of reaching their first World Series since 1988.
His previous contract became guaranteed for the 2014 season when the Dodgers reached the National League Championship Series last October. The team has been negotiating an extension with Mattingly since the end of the 2013 season, but things haven't exactly gotten along smoothly.
Mattingly was heavily criticized for several miscues during the team's playoff run last year, leading to speculation that the front office would consider alternatives this winter. The Dodgers decision to fire bench coach Trey Hillman -- handpicked by Mattingly -- appeared to further jeopardize a long-term agreement, and Mattingly gave an "awkward" press conference that seemed to indicate negotiations were at a standstill.
Since a deal is expected to be finalized soon, the two sides seem to have worked through those obstacles, but nothing has been officially announced.