Titans coach Mike Munchak threw the position open for competition during the offseason. Hasselbeck had a solid year as a free agent addition in 2011 and has been mentoring Locker, the former first-round pick.
The quarterbacks alternated reps during the first practice Saturday, a pattern that is likely to continue until a decision is made. Munchak says he wants that decision made by the third game of the preseason, Aug. 23 against Arizona, for the good of team chemistry and preparation for the regular season.
"I think we have no choice but to. We can't wait past that,'' Munchak said. "I mean in any position, again just philosophy wise, you got to do what's best for your team and you got to make a decision.''
In his mind, there is no such thing as overdoing the analysis of picking a starting quarterback.
"You're looking at everything. You can't overanalyze. It's not just the quarterback, there's everything,'' he said. "You're kind of taking it all in on the field. You can see things on the field obviously you cannot see on film. That's the type of stuff . the interactions, how they respond to each other, how they respond after maybe a couple of bad plays, how they take the coaching. Those are the things you see on the field - the body language.''
The choice won't be an easy one, given that Hasselbeck, who turns 37 in September, turned in his best season since 2007 after he signed with the Titans as a free agent following last year's lockout.
In his 13th NFL season, Hasselbeck completed 319 of 518 passes for 3,571 yards with 18 touchdowns to 14 interceptions.
And while he is keeping the seat warm for Locker, and the two have become good friends, Hasselbeck is preparing himself to try to hold on to the job a while longer.
During the offseason in the Seattle area, Hasselbeck scaled back on "fun'' events to put even more focus on getting ready for the 2012 season.
"I've got some neighbors in Washington - we do a homemade triathlon each year, and I passed on that. I skipped out on that. There was no wakeboarding or any of that kind of stuff,'' Hasselbeck said.
For Locker, the offseason changed as well. He stayed in Nashville during his break between mini-camps and training camp, mostly because his wife Lauren gave birth to the couple's first child, a daughter named Callie Jo, on July 17.
Locker had the misfortune of coming to camp as a rookie with no offseason thanks to the lockout.
"For us that were rookies last year, it's a lot different dynamic this year,'' Locker said. "We're able to get familiar not only with the playbook, but the coaching styles, what they want out of certain plays, what we're trying to achieve within our offense or our defense. Last year, there was a lot (of nerves), just because there were a lot of unknowns. You didn't know what to expect.''