In many ways, it’s a fine line between the very top of the men’s game and those players toiling below the top 100.  Marat Safin could probably attest to just how big the gap can feel at times.  In 2006, Marat has struggled to find his game, fitness and ranking after a knee injury sidelined him for the second half of 2005.  Despite enormous talent and charisma and two Grand Slam titles on his resume, Safin has not simply waltzed back into the top 10 in 2006.  Safin’s had a lackluster year at best, especially for someone with his skills.  His semifinal showing at the 2006 U.S. Open and strong play in the Davis Cup Semifinals versus the U.S.A. could bode well for Safin’s play going into 2007.  As Kim Clijsters did last year, Safin has announced that he only plans to play for 4 more years because he doesn’t see himself competing in his thirties.  Staying healthy will be key because it doesn’t sound as if Marat has the energy to go through another long injury layoff.  But staying inspired will be Safin’s biggest challenge.  Safin seems to shine under the bright lights on the big stage and disappear under the rafters when his game is a little off and there’s not as much on the line.  For his sake and for the sport of tennis, let’s hope Marat feels the buzz under his feet over the next few years and capitalizes on his talent with another Slam or two…