Garoppolo is recovering from a calf injury suffered on October 3. Lance started in Garoppolo's place the following game, on October 10, and sustained a knee sprain.
The 49ers expected Garoppolo to be ready to return this week. Lance's absence shouldn't come as a surprise. The recovery timeline for the younger quarterback was estimated at about one to two weeks, bringing into question his availability for this weekend's matchup against the Indianapolis Colts at Levi's Stadium.
San Francisco will hold three more practices this week, with the next one scheduled for Wednesday afternoon. The Niners own a 2-3 record after losing three consecutive games, sit in third place within the NFC West, and need to start winning again to climb back into the playoff picture.