For what it's worth, I took a look at the WS/48 and minutes played numbers for our projected starters for next year and did some basic math / estimation.
Bradley: 2200 minutes (.05 ws/48) --> 2.29 WS
Rondo: 2000 minutes (.125 ws/48) --> 5.21 WS
Green: 2800 minutes (.09 ws/48) --> 5.25 WS
Jordan: 2100 minutes (.145 ws/48) --> 6.3 WS
Sullinger: 2000 minutes (.140 ws/48) --> 5.8 WS
That's 21.85 wins. How many wins could you expect to get from the bench?
I'm guessing another 5-10, at most. Much less if we trade Lee and / or Bass.
If the remaining players play at a combined 0.050 ws/48, then that would translate as 8.9WS. If they played at 0.070WS, it is 12.5WS. Of Bass, Terry, and Lee, Lee had the lowest WS/48, so if the bench averaged Lee's .082, that's 14.7WS.
Let's say Bradley's ws48 is the .085 of his breakout season. That adds 1.6WS. Let's be crazy optimists and say Green can produce at .12 ws/48. That adds 1.75WS. Let's say you under-estimated Rondo/Jordan/Sullinger by another 1WS.
21.85+14.7+1.6+1.75=39.9
Rondo getting back to being a .150 ws48 player for 2800 minutes, upgrading one of the other starters to a 9-11 WS player, plus some other improvement, and you're getting into territory where the team adds up to about 50WS.
Does this math suggest to you that the team has at least an outside shot at being a contender in 2014-2015? It will take some luck, but so does building through the draft.