Smith, the Ravens’ first-round pick out of Colorado, got hurt while covering a kickoff in the first quarter of the team’s 35-7 victory over the Pittsburgh Steelers.
X-rays taken on his ankle were negative, but Smith is still expected to be sidelined for an extended period.
“Jimmy is the one guy that had an injury that was something a little more serious,” said Harbaugh, who said that Smith got caught up in a pile while covering the kick. “He’s in a boot, he’s on crutches, he had an MRI. He does have a high ankle sprain. That’s going to be a few weeks. We’ll just have to see how that plays out. Hopefully, he’s a quick healer, but that was a tough one.”