Thank you so much. If they do elevate one with only a week or two practice it would be Valentine. He could probably fit in a rotation quickly, if healthy. Mitchell would need to fit in with the offense.
According to reports, both have been in the facility on a regular basis all season long, so both are likely to be mentally up-to-date with the current state of this year's playbook (neither will likely be lost). For me, then, it's all about which might contribute greater game-day value than the player they might replace on the roster.
1) Valentine hasn't experienced practice speed, much less game speed, or contact in nearly four months.
-- VERSUS --
(likely)RJF, who has.
..... What are the realistic chances that a mere three weeks of practice makes Valentine a significantly superior option to RJF?
2) Mitchell is in the same position as Valentine in terms of speed of play and contact.
-- VERSUS --
One of Britt or Dorsett.
..... What are the realistic chances that Mitchell, after three weeks of practice, might be a significantly superior option to either Britt or Dorsett?
At this point, I'd lean toward Mitchell.
However, the calculations may change substantially if ..
A) Branch won't be healthy in time for the playoffs (Valentine possibly needed more)
-- OR --
B) Britt outperforms most expectations this afternoon (in which case, "Suck it, Dorsey!"). Mitchell possibly needed less
The other thing is that, due to getting the three week roster exemption for practice, there's no harm in bringing one or the other in for that period since there's no
requirement that the practicing player be activated at the end of the three weeks (they could still be sent back to IR if not needed). This, of course, assumes that both are sufficiently recovered from their injuries that practicing won't pose an undue risk of a setback.
So, if Branch is healthy AND Britt performs very well, the Pats could still have one of Mitchell/Valentine practicing, and available to be activated just in case (for three weeks).
In that circumstance, I'd probably still go with Mitchell as the "just in case" guy. Even if they end up not needing him, it might be of more benefit (than it might be with Valentine) to see how well he performs in practice since that may help to eliminate a variable in next season's player-acquisition calculations wrt FA and draft.