The Boston Celtics will be in an intriguing situation when the lockout lifts. With just six players under contract for 2011-12 they are already well over the 2010-11 salary cap level. Will they still be able to put together another championship run?

First off, the good. Four of those six players under contract are the starters at the 1-4 positions: Rajon Rondo, Ray Allen, Paul Pierce, and Kevin Garnett. Combined those four are on the books for $56.6 million. The other two players under contract are Jermaine O’Neal – who at $6.2 million could be the starter at center if he can stay healthy – and second-year guard Avery Bradley ($1.5 million).

Forward Jeff Green, acquired in the Kendrick Perkins trade, is a restricted free agent with a Qualifying Offer of $5.9 million. Boston also drafted Purdue teammates JaJuan Johnson and E’Twaun Moore in last month’s draft, who could be slotted at $1.0 million (27th pick, first round) and $0.5 million (rookie minimum).

Forgetting the lockout for a moment, and the point that any new contracts will be signed under a different set of still unknown rules, let’s take a look at the Celtics’ possibilities for filling out their roster under the old rules. Let’s assume they keep Green at about the Qualifying Offer, then sign Johnson and Moore. That puts them at $71.8 million – luxury tax levels – for only nine players.

Two of those nine players are rookies, who typically aren’t relied upon very much both in Coach Doc Rivers’ system and on the rosters of teams with championship aspirations in general. Bradley, for example, played a grand total of 162 minutes in 31 games, spending most of his rookie season in the D-League. Of the 52 points he scored as a Celtic, 20 came in the final game of the season that held no meaning to Boston.

That divides Boston’s roster into three parts: the veterans Rondo, Allen, Pierce and Garnett; the relative newcomers in Green and O’Neal; and the unproven in Bradley, Johnson and Moore.

Given the fragility of O’Neal and the general age of the starting lineup – Garnett, O’Neal, Allen and Pierce average 34 years of age – Rivers will absolutely push to add some veteran big men, preferably ones that can be counted on for rebounding and defense.

Under the old rules the Celtics could also convince Glen Davis to re-sign with the Bird Exception, which would give them another post player, though not a rebounding, defensive beast like they need. If that’s the route they go, they will need to make Davis a better offer than he can get elsewhere since money is likely a major factor in his decision-making process at this point in his career. That could mean overpaying Davis, just to keep a post asset who knows the system, even though he doesn’t fit the most dire need.

Whether the Celtics decide to keep or not keep Davis they are already over the luxury tax level and could have only the Mid-Level Exception to use ($5.8 million last season by the old rules; unknown whether it will survive in a new CBA). They would also have the Bi-Annual Exception they could possibly use ($2.1 million last season by the old rules; unknown whether it will survive in a new CBA).

In the past the Celtics have shown no hesitation to use either exception, so given the needs they would have to fill (in the post and backup point guard) it seems a safe bet they would use both exceptions if available.

If the Celtics were to do all of those things, they would have 10 players under contract (maybe 11, if they split the MLE between two players) and a payroll of north of $80 million. Teams are required to carry at least 13 on the roster and the league as an average needs to carry 14.

This leaves the Celtics in a precarious situation. With three of those players – the aforementioned Bradley, Johnson and Moore – perhaps not quite ready to be rotation players, they still need plenty of veteran help to fill out the bench and nothing but minimum contracts to offer. Management could consider trading one of the starters, perhaps Allen or Garnett, in an attempt to return two players who could make an impact, but that’s not a move that will make them a better team.

Boston may end up being stuck with a very weak bench, much like the situation the Miami HEAT found itself in last season. If the Celtics suffered an injury of any serious length of time to one of the core four starters, they may find themselves dropping like a rock in the standings.

Remember, this whole scenario is under the old rules. Under new rules the Celtics may be even worse off. Even with salary rollbacks, should that happen, the percentage of the cap used would remain the same, leaving the Celtics with a limited amount of money to fill out the roster with the veterans they need. If the cap exceptions – the MLE, BAE, restricted free agency or Bird Rights – go away or are modified, they may not even be able to add everyone they need from the scenario above.

If the 2011-12 is lost – which would be a monumental disaster for all parties and fans – Boston may actually be in a slightly better position. Allen, Garnett and O’Neal – a combined $37.5 million – come off the cap following the 2011-12 season, leaving the Celtics with just $29.4 million owed to Rondo, Pierce and Bradley in 2012-13 as of now (note this does not include Johnson because he hasn’t signed, but would add about another million to that total).

Boston planned for a rebuilding session in the summer of 2012 when they re-signed Allen and then signed Shaq and Jermaine O’Neal in the summer of 2010, rebuilding around the talent of Rondo and the veteran leadership of Pierce. If there are games in 2011-12 – and everyone of course hopes there are – it will be very interesting to see how the Celtics approach free agency to fill out the rest of their roster, no matter how the new collective bargaining agreement dictates the rules.