SANTA CLARA, Calif. -- San Francisco 49ers rookie quarterback Trey Lance stepped in for starter Jimmy Garoppolo to open the second half of Sunday's 28-21 loss to the Seattle Seahawks.

Moments after Lance took the first snap of the third quarter, the Niners announced that Garoppolo was dealing with a right calf injury. Originally listed as questionable, Garoppolo did not return to the game. He told reporters after the game that he will undergo an MRI on his calf and hopes "it's just a couple of weeks or something."

Garoppolo went 14-of-23 for 165 yards with a touchdown and an interception in the first 30 minutes, as the Niners jumped to a 7-0 lead but entered the half tied at 7. Garoppolo was 6-of-6 for 70 yards and a touchdown on the first drive but went 8-of-17 for 95 yards and an interception the rest of the way.

When the Niners came back out to start the third quarter, Lance took some snaps from center Alex Mack on the sideline and chatted with coach Kyle Shanahan and quarterbacks coach Rich Scangarello. Garoppolo offered a quick hug and a pat on the head to Lance before he went on the field.

Lance finished 9-of-18 for 157 yards and two touchdowns. He also added 41 yards on the ground on seven carries.