Marcus Mariota is well aware that the heat is on and that the Tennessee Titans can’t lose much more ground.The fifth-year quarterback looks to help his club halt a two-game slide when the Titans (1-2) visit the Atlanta Falcons (1-2) on Sunday afternoon.Tennessee averaged just 12 points in back-to-back losses to the Indianapolis Colts and Jacksonville Jaguars. There was little time for Mariota to thrown in a 20-7 setback against the Jaguars on Sept. 19 as he was sacked nine times, raising the season total to 17.Mariota accepted part of the blame for the sacks and said he used some of the extra time off to address his footwork and movement.”If I can do a better job of moving in and around the pocket, I can help our guys up front and deliver the football to our guys to make plays,” Mariota told reporters recently. “At any point and time you can get better. Through the course of a year, through training camp, sometimes the fundamentals get lost. And coach (Mike) Vrabel does a great job of reiterating to us to get back to the basics.”Mariota has passed for 706 yards and four touchdowns without being intercepted this season. Still, the sentiment is that the second overall pick in the 2015 NFL Draft is again not living up to his billing — this time as he plays out the final season of his contract on a fifth-year option worth $20.9 million.Tight end Delanie Walker hears the chatter around Nashville and wants to remind people that more than one person is responsible for a team’s struggles.”I am very confident in (No.) 8 — he has been getting it done,” Walker told reporters of Mariota, while referring to him by his uniform number. “It is tough being a quarterback in this league — you take all the blame, no matter what. And that guy, he’s not going to say anything about anyone.”It doesn’t matter if someone dropped a pass on third down, or he got sacked multiple times. He is going to just say it was his fault, and he has to do better. And that is the sad part.”The Falcons have issues of their own after suffering a 27-24 road setback against the Indianapolis Colts last Sunday. Atlanta committed 16 penalties for 128 yards.The defense suffered a huge blow by losing standout safety Keanu Neal for the season with a torn Achilles tendon, and the offense was ineffective in the first half while digging a 17-point deficit.Quarterback Matt Ryan has topped 300 passing yards in each week but he isn’t impressed with his squad’s collective play through three games.