49ers' left guard battle heats up mid-camp with lineup changes
San Francisco's training camp is tightening the competition for the starting left guard, with Connor Colby initially in the lead but veteran Robert Jones running with the first team after Wednesday's practice; injuries to Carver Willis and Brett Toth limited movement, and coach Chris Foerster planned more interior testing to evaluate Colby against different defenders, so Jones and Colby remain the top contenders with more entrants possible when Willis and Toth return.