"They said eight weeks; I said six," the San Francisco 49ers' tight end said. "And I'm excited. These last couple days have definitely progressed forward and made me very optimistic about returning to the field of play.

"When I first got hurt, my mindset was that I'll be back. And I'm going to continue to keep that mindset because I definitely feel like I'm going to be on the field here sooner than later."

Kittle sustained the injury in Week 8 on Nov. 1.

Kyle Shanahan said he hopes to have both Kittle and Jimmy Garoppolo back by the end of the season.