Tennessee signed Greene to a three-year, free-agent deal worth $10 million with $4.5 million guaranteed, and looked to him to be a short-yardage, goal-line back who could take Johnson out of some situations.
Greene got hurt in the opener, needed knee surgery, missed six games and needed a few more to get back close to himself.
Johnson's 3.9-yard average per carry was certainly not worth his $10 million, 2013 salary and it's the primary concern when the team decides whether to keep him at an $8 million salary in 2014.
But he deserves credit for how he did in short-yardage situations in 2013.
Greene had 12 carries where 1 or 2 yards would get the Titans a first down, and he converted nine of them (75 percent.)
Johnson had 22 carries where 1 or 2 yards would get the Titans a first down, and he converted 16 of them (72.7 percent.)
That's better than most of us would have presumed, I suspect. It's the second-best percentage Johnson has produced in such situations in his six-year career, trailing only his 90 percent in 2011.