They aren't an automatic pick for the playoffs and if he's not "the man" they won't even come close to making it there. This team is very thin in the secondary(they are toast if they have to play for an extended period of time without Springs) and along the o and d lines. Definitely not the makings of a champion. With their starters healthy they can compete but all it's going to take is a couple of injuries to send this team into a tailspin. I pick em to finish 3rd or 4th in the division as it is. If they have to go with Betts or Duckett, make that 4th and a losing record.
Things are so bad with this team on the O line(talking backups) that they just signed a guy who played for the Texans last year!
So, limiting his workload in anticipation of saving him for the playoffs would be foolish. They are far from being a lock to get there and Portis will be the man who gets them there if they make it.
Their chances to make the playoffs and win playoff games are certainly enhanced by a healthy Portis in the lineup, but let's not forget that the names of the last 5 starting RB's for the Super Bowl champions were:Jerome Bettis (34-year old version)
Corey Dillon
Antowain Smith
Michael Pittman
Antowain Smith
This is not exactly the cream of the RB crop in any of those seasons, even by fantasy football standards. Betts and Duckett are capable IMHO of combining to carry the load if Portis can't. It may not be awe-inspiring, but the team can win games with them.
The problems will start, as you have correctly pointed out, if they lost o-linemen to injury or if Brunell is injured. They have the least amount of proven depth at those two places on the roster (along with CB).
Help me to understand your criticism of the teams' expenditure of money this offseason? What o-lineman was available for signing in FA that was good enough for them to want to provide good depth, and yet not so good that he wouldn't want to sign elsewhere for a chance to start (which he wouldn't get with this team)? I'm not saying one or several don't exist, I'm just wondering who you have in mind.