Thomas’ forearm injury leaves 49ers with roster decision to make

NASHVILLE, Tenn. — Cornerback Ambry Thomas might have been in an uphill climb to hold onto a 49ers roster spot this summer. Now, he faces another obstacle in order to log a fourth season with San Francisco. Thomas sustained a fractured right forearm Saturday night in the 49ers' 17-13 preseason loss to the Tennessee Titans, which places his tenure with the 49ers in serious doubt. Coach Kyle Shanahan said the injury is expected to keep Thomas out of action for "some time." Thomas was injured while attempting to make a tackle in the second quarter. The 49ers must make a decision in the coming days whether to place Thomas on injured reserve or whether to waive him with an injury settlement. They likely will add another cornerback to fill a spot on the team's 90-man roster. Thomas was in the starting lineup for the 49ers' preseason opener against the Titans. He was credited with one tackle in the game. Cornerbacks Charvarius Ward, Deommodore Lenoir, Isaac Yiadom and Darrell Luter did not suit up for the game, as the 49ers kept many of their top players on the sideline. In addition to those four players in front of him on the depth chart, Thomas also was in competition against...