NASHVILLE – There is no doubt the news that the San Francisco 49ers will face Jake Locker instead of Ryan Fitzpatrick on Saturday will change the team's defensive plans.Locker is much more mobile and runs some read-option plays. Locker was playing well before he hurt his hip and missed the past two games. The Titans were 3-1 with Locker and 0-2 without him."Well, I've always thought this, he's like a running back with his ability to run the football," 49ers coach Jim Harbaugh said about Locker on Wednesday.