The Boston Celtics and Miami Heat return to South Beach tonight for Game 5 of the Eastern Conference Finals. As of right now, a matter of hours before the first tip, there is no clear indication as to whether Chris Bosh will be in the lineup for the Heat or not.

Bosh hasn't played a game in this series so far but many expect him to as he continues to recover from an abdominal injury suffered against the Indiana Pacers in Round 2.

Without him in the lineup, the Heat and Celtics have battled each other to a 2-2 tie heading into Game 5. Each team has won their home games relatively comfortably, despite going to overtime in Boston in Game 4.

Doc Rivers has said that the Celtics have prepared for Bosh during each game of this series as they also expect him to feature at some point. When Bosh is back on the court, this is likely what Rivers is preparing for:

On Defense:
Chris Bosh is definitely not the most physical of presences in the paint. He doesn't dominate either end like a Shaquile O'Neal or even Roy Hibbert. However he does play great defense from the power forward position with his length and intelligence.

Bosh provides his team with two important aspects when defending the Celtics. The most obvious matchup that he helps the Celtics with is Kevin Garnett. Bosh is very similar to Garnett on both offense and defense. Defensively, against Garnett, he has the length and agility to keep him from the rim while also challenging every outside shot that Garnett attempts.

It's not only the Celtics' bigs who will be affected by Garnett's return however.

While Joel Anthony, Udonis Haslem and Ronny Turiaf are respectable defenders, each with a different skill-set, none of them are capable of making Rajon Rondo hesitate consistently when attacking the rim. Rondo attacking the rim has been an important scoring avenue for the Celtics so far in this series.

If Rondo can't consistently score inside, the Celtics will have trouble keeping up with the high-powered offense of the Heat. That high-powered offense has limped through the last two games, but should change dramatically if Bosh returns.

On Offense:
Bosh gets a lot of criticism from the casual NBA fan who will often refer to him as the half of the Heat's two-and-a-half men cast. While it is true that Bosh is not on the superstar level of Dwyane Wade and Lebron James, on this roster he is just as important to the team's success.

When Pat Riley put together this Heat roster, he put a huge amount of pressure on the big three to carry the team because they could not afford quality role players. This year's role players are definitely better than last year's, with Shane Battier and Ronny Turiaf added to Udonis Haslem, Mario Chalmers and Joel Anthony.

However, those role players still struggle to really impact games if their star teammates aren't at 100 percent. Bosh is essentially the high quality role player for the Heat as when he plays well, the team generally wins.

So far the Celtics have looked to shut down Dwyane Wade while letting Lebron James get what he can. James alone can't beat the Celtics, and without Bosh, the Celtics can focus on preventing Wade from having an impact on the game. With Bosh back, the Heat have a second quality scorer who can take the pressure off James and force the Celtics to play each player straight up. Taking away Wade does nothing if Chris Bosh simply steps into his place.

Bosh's own impact will hurt the Celtics, but also his presence on the court returns the Heat to their natural spacing on offense.

He won't be backing down defenders in the low post like Dwight Howard, but he does give the team an inside scorer, from the elbow or high post, without Lebron James having to play out of position. That puts greater pressure on the Celtics whole defense.

If the Celtics defensive integrity isn't in tact, they will give up position to either of the perimeter superstars or Bosh inside. Nobody fears Joel Anthony, Udonis Haslem or Ronny Turiaf's ability to beat you by scoring the basketball, but they certainly will fear Chris Bosh.

Kevin Garnett has the capabilities to cover Bosh but Garnett's minutes have been a worry as of late. Stressing him on both sides of the court could worsen that because Bosh, even returning from injury, should have more in the tank at this stage in his career than Garnett.

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