If true, then I'll be the first to admit I was wrong; I thought there was close to zero chance that Mankins would be activated for the game against the Browns. He must have done very well in practice this week; Belichick talks about the difference between being in shape versus being in football shape, getting your timing down, etc.
The other thing I am thinking about is that perhaps BB wants Mankins to get some live reps in before the Steelers game. As for Wheatley, it's really too bad; it sounded like he had a very good training camp but BB must have figured he can't do much good for the team if he's constantly sidelined with an injury.