Lewis missed Sunday's game against Cincinnati, ending his streak of playing in 57 straight games.
The 36-year-old veteran did not talk to the media on Tuesday but said in a statement that he is "taking every opportunity to get treatment on my foot to prepare to play on Thursday."
He watched Sunday's game from the sideline, cheering his teammates and offering encouragement. He would prefer not to do so again Thursday night when the Ravens (7-3) face the 49ers (9-1).
Lewis says as a team leader, "it doesn't sit well with me to be on the sidelines."
Lewis leads the Ravens with 68 tackles.