It may be a difficult reality for diehard Boston Celtics fans to accept but as currently constructed, the C’s are simply not a championship contender. It would be easy to simply blame injuries and unfamiliarity, but the truth is that Boston needs to make some roster changes if it wants to contend once more with the current core.

Given the Celtics lack of cap room and financial flexibility, signing one of the 2013 offseason’s marquee free agents is practically impossible, but that does not mean this team cannot improve this summer. With the exception of the final move listed on this slideshow, all of the moves I’ve listed would be possible in some form without getting rid of Kevin Garnett and Paul Pierce

Offense and rebounding may be the main areas of concern for Boston after their disheartening first-round loss to the New York Knicks, but there are other areas that the Celtics must look to address before they can reclaim their status as a member of the league’s elite.

No single move listed here will turn Boston back into contenders overnight, but some combination of them will go a long way towards setting up another title run.

Note: In most of the situations I discuss, Pierce and KG would return for one final season together.

Contract information courtesy of Hoopsworld.com

The Boston Celtics have no shortage of guards on their roster, but what is in short supply for the C’s are point guards. The only true point under contract is Rajon Rondo, and the 2012-13 season proved that ball-handling duties cannot be delegated to Jason Terry, Courtney Lee and Avery Bradley.

Terry, Lee and Bradley are all talented players, but they are all best suited to be shooting guards and are not natural facilitators and playmakers. While Rondo is capable of playing superhuman minutes in the postseason, he will be coming off of a brutal injury and needs a quality backup who can step in and run the offense for a few minutes at a time.

When Boston stunned the basketball world by coming within one win of making the 2012 Finals, they had cagy veteran Keyon Dooling coming off of the bench. Dooling averaged just 10.6 minutes per game and 2.8 points, but he made the right pass, played stingy defense and shot 39.3 percent from beyond the arc during the postseason.

Boston needs a guard with meaningful playoff experience under his belt who can find the open man, run the pick-and-roll and not be a complete defensive liability the way Terry was this past season.

Fortunately, there are plenty of low-cost options available in free agency for the C’s to consider.

Cleveland’s Daniel Gibson has averaged 6.4 points and shot 40.7 percent from beyond the arc in the playoffs, while making the 2007 Finals with the Cavaliers. He has battled injuries recently and is more shoot-first than pass-first, but he is young and can shoot lights out from the perimeter.

Portland’s Eric Maynor is an option as well. Maynor was buried on the Oklahoma City bench before being dealt at the trade deadline to the Trail Blazers and experiencing a resurgence. In the Thunder’s run to the Western Conference Finals in 2011 he averaged 4.8 points and 2.2 dimes in 12.9 minutes per game. Maynor is more of a pure point guard than Gibson and can run the pick-and-roll as well as find open shooters on the wing by attacking the paint.

Other, more experienced options include Utah‘s Jamaal Tinsley, Los Angeles’ Chauncey Billups (a prodigal son of the Celtics), or OKC’s immortal Derek Fisher.

The Celtics’ lack of size has been painfully obvious over the past few seasons as Kevin Garnett has been forced to battle inside virtually by himself against opposing big men. The surprising rookie success of Jared Sullinger will help on the boards, but Sully is still quite young and has a troubling history of back injuries.

The two best options that should be available for Boston with the 16th overall selection are Louisville’s Gorgui Dieng and Duke’s Mason Plumlee, a pair of upperclassmen with plenty of meaningful experience for national championship contenders.

While helping Louisville to the 2013 NCAA title, Dieng averaged 9.8 points, 9.4 boards, two assists and 2.5 blocks while shooting 53.4 percent from the field. He developed significantly under Rick Pitino, becoming a strong jump shooter and a skilled post passer by his junior season.

Dieng will never be a star in the NBA, but he is a good role player capable of playing both power forward and center who should be able to step in and contribute immediately for a team like Boston in desperate need of a big man.

Plumlee’s senior season in Durham was a tremendous success, as he verged 17.1 points 10 rebounds, 1.9 assists and 1.4 blocks while shooting a blistering 59.9 percent from the floor.

He began his career as an offensive liability but under Mike Krzyzewski he developed a reliable low post game and became a decent foul shooter capable of capitalizing on his opportunities at the line.

Plumlee is less skilled than Dieng, but he is a great rebounder on both ends of the floor and runs the floor as well as any big man in college basketball. He needs to bulk up, but is far more NBA-ready than someone like Fab Melo (then again, you and I might be more NBA-ready than Fab Melo).

By taking one of these two big men, Boston guarantees themselves a talented young piece who won’t make much of a dent on the salary cap. The 2012-13 rookie salary scale dictates that the 16th overall pick earns $1.37 million in their first year, then $1.67 million and $1.74 million in the following two seasons.

The 2012-13 New York Knicks were a good defensive team, there is no denying that, but that’s no excuse for Boston averaging a horrid 82.3 points per game in the playoffs. That mark is dead last among playoff teams behind Milwaukee and Los Angeles, both of whom were swept, by a full three points per game.

It is a testament to the Celtics’ defense and the sheer will of Kevin Garnett and Paul Pierce that the team lasted six games, but if Boston is going to return to contention they are goin