I never want to hear chronic back problems in the same sentence with a player that is turning 29-years old and has 2,033 career carries. He has low RB1 value and it is difficult to handcuff him with both Robert Turbin and Christine Michael backing him up.
Lynch had the most amount of TD's in the league with 17 last year. You have to believe that he won't repeat that level of performance with additional receiving threats and losing carries to back-ups. It's hard not to see him putting up double digit TD's., over 1,000 yards, and many receptions. He is a safe pick for an all-around RB on a solid team.
Lynch has been as consistent as any running back in the league over the last four seasons, having topped 1,200 yards in each of those seasons and piled up 56 total touchdowns during that span as well. He turned 29 in April, so there is some concern that he will start to fade, but there has been no evidence of that yet, and when factoring in his team's quarterback, Russell Wilson, and new tight end Jimmy Graham, I see Lynch's easy touchdown opportunities increasing. His safety and high floor is what you're paying for here, and I will take it.
Lynch has averaged 12 rushing TDs over the past 4 seasons and finished as the #3 RB in fantasy in 2014. There was talk of Lynch retiring due to chronic pain caused by compressed cartilage in his back, but he signed a new three-year, $31 million contract in March. Now 29 years old, so some tread on the tires. The big question fantasy league managers want to know is how will the addition of TE Jimmy Graham affect Lynch's fantasy numbers and I think that it will hurt his value. Over the past 4 years, Lynch has averaged 295 carries per season and "Beast Mode" is not a sure thing with an increased passing game with Graham at TE. I have Lynch projected at only 252 rushing attempts this season, but he is still at top 5 RB.