FOXBOROUGH, Mass. -- The New England Patriots have signed running back Dion Lewis, a surprise contributor for them this season, to a two-year contract extension through the 2017 season.

Lewis, 25, can make up to $4.8 million in new money over the two new years, a league source told ESPN's Field Yates, and the deal also includes a $600,000 signing bonus. His base salary will be $800,000 in 2016 and $1.2 million the following year, the source said.

"It was a good feeling," Lewis said Thursday of signing the extension. "Still have a lot of work to do."

The 5-foot-8 Lewis has been a threat out of New England's backfield and in the passing game this season. He has 30 carries, 15 receptions and two touchdowns in the Patriots' 3-0 start.

Asked what led him to sign an extension now instead of waiting to become an unrestricted free agent after the season, Lewis said, "They gave me a chance and that's all I can ask for. They gave me a chance, so it's on me to repay them as well. They showed a commitment to me and I just have to honor it and keep on going out there and making them right."

Dion Lewis has added spark to the Patriots offense with his ability to run and catch out of the backfield. Jerome Davis/Getty Images

The Patriots had signed Lewis to a one-year "future" contract for 2015 on Feb. 6 after Lewis had spent most of the 2014 regular season out of football (he also missed 2013 with the Browns due to a broken leg). Lewis also received some level of interest from the New York Giants in the offseason.

By the end of 2015 training camp in New England, Lewis won a three-way competition with 2014 fourth-round draft pick James White and free-agent signee Travaris Cadet to become the team's top "passing back", a role previously held by Shane Vereen, who had signed with the Giants in free agency.

No Patriots running back has played more than Lewis through the first three games of this season, as he's been on the field for 150 of 223 offensive snaps. At 5-foot-8 and 195 pounds, he has quickly become a fan favorite with his decisive cuts and explosion.

During NBC's broadcast of the Patriots-Steelers season-opener, analyst Cris Collinsworth relayed that Tom Brady told him that Lewis "is about to become a cult hero here in New England with his quickness."