Vic Fangio says what he thinks, but the 49ers defensive coordinator is more likely to tell you what he knows.
Fangio revealed a few nuggets before Tuesday night's practice session.
Craig Dahl will start at free safety alongside Donte Whitner on Thursday night, when San Francisco opens the preseason against the Denver Broncos at Candlestick Park. Dahl, a free-agent signee from the Rams this offseason, also took the initial reps with the first unit when training camp opened but has since watched Trenton Robinson, C.J. Spillman and Eric Reid take their turns alongside Whitner.
Also making the start will be defensive end Demarcus Dobbs, who will be filling in for veteran Justin Smith. Dobbs, who also appears on special teams, will be given the chance to prove himself as an able backup. Smith, meanwhile, has missed practice this week with an undisclosed injury, though he has been seen with a wrap around a finger on his right hand.
Also on the defensive line, Lawrence Okoye will likely play in his first ever football game.
At 6-foot-6, 304 pounds, Okoye and his No. 78 jersey stick out on the practice field. The British Olympian -- he owns the discus-throwing record -- would rather be noticed for his heady and physical play, however.
"The more he is thinking out there, it affects his technique and how intense he can play, how confident he is," Fangio said of Okoye picking up the physical and mental aspects of playing along the defensive line. "His process isn't as fast as somebody else's that has got experience."
Fangio said Okoye's time on the field on Thursday could just depend on how often the 49ers offense is on the field. He referenced a 2012 preseason game in which the defensive unit only saw 52 plays of action. Moving that number closer to 80 would increase the likelihood of Okoye's debut.
"He's gotten better from day one," Fangio said. "But it's all relative. We're going to try to get him into the game. How much, I don't know yet."