SANTA CLARA, Calif. – Earlier Thursday, San Francisco 49ers defensive coordinator Vic Fangio said nose tackle Glenn Dorsey would try to practice some. But later in the day, the 49ers indicated that Dorsey had missed his second straight practice day because of a hamstring injury.Because hamstrings are easily aggravated, the odds are against Dorsey playing at Tennessee on Sunday. Tony Jerod-Eddie will likely start, and the team will likely either add Mike Purcell from the practice squad or activate Quinton Dial from the physically unable to perform list.