The Rangers won’t make a splash when the free-agent market opens at noon. The limited amount of cap space available simply doesn’t allow for the big-market team to be in play for the big boys. Of course, given history in the form of Wade Redden, Scott Gomez, Chris Drury, Bobby Holik, Alexander Frolov, Patrick Rissmiller and Ales Kotalik, to name but a few, perhaps the constraints on general manager Glen Sather are every bit as much a blessing as a curse. Still, the Blueshirts do need to produce a ripple in the pool, even if not necessarily today. The roster isn’t deep enough and the prospects aren’t sure enough to enter the lengthy season-opening trip without cost-effective reinforcements to fill lineup holes that will be created by the absences of Ryan Callahan and Carl Hagelin, who are both recovering from offseason shoulder surgeries. The Post has learned the Rangers have held discussions with fourth-line, checking-oriented center Dominic Moore, who is pondering a return to the league after sitting out last season after the death of his wife, Katie, who lost her two-year fight against a rare form of liver cancer on Jan. 7. A source has confirmed Moore, who will turn 33 next month, had spoken extensively with the Rangers last year before the lockout and likely would have signed with the club if his wife’s medical condition had allowed. Moore, who began his career with the Blueshirts in 2005-06 as the center of the HMO Line between Ryan Hollweg and Jed Ortmeyer, earned an average of $1.1 million his last three seasons. That’s a number the Blueshirts can accommodate.