Mike Mularkey called the Titans’ offensive struggles “very fixable,” and the tool of choice has been an ax. The Titans have cut back on plays and focused on fundamentals during their weeklong stay in Arizona, in an effort to sharpen execution on offense after sputtering to 62 total yards in the second half of a 12-7 loss to the Cardinals on Sunday at University of Phoenix Stadium. “I don’t think you can change a whole lot of things, as far as all the stuff that you’re doing,” Titans offensive coordinator Terry Robiskie said after practice Thursday at Arizona State University. “But I think again, somewhere you can stop and sit down and say, ‘Well, slow down. Let’s go back to the basic fundamentals of whatever it is.’” He cited the power running play “double,” as an example. “That’s a simple play,” Robiskie said. “And maybe that’s just, as opposed to having six plays that you’re going to run, three to the right and three to the left, let’s take that one play and go run that play six times. Let’s go back to the fundamentals of that one play and run it six times.” The Titans (8-5) trail the Jaguars (9-4) by one game for first place in the AFC South with three to play. They visit the rejuvenated 49ers (3-10) on Sunday at Levi’s Stadium before returning to Nashville for the final two games of the regular season, against the Rams and Jags.