There are signings that make complete sense, signings that are head-scratchers and signings made to specifically address a specific need. Count the addition of Louis Murphy as the latter.

“I can do a lot of things,’’ Murphy said recently as he acclimates to playing wide receiver for the Giants. “I can go inside, play outside. I can do it all. But they do like to stretch the field and I like doing that.’’

The potential to stretch the field is why Murphy is on board. He has kicked around the NFL since 2009, when the Raiders made him a fourth-round draft pick out of Florida. Three years and 57 games (24 starts) with the Raiders and last season with the Panthers produced 115 catches for 1,707 yards and seven touchdowns, with Murphy never really establishing much of anything other than that he was very fast and not very consistent.

The Giants took a low-risk chance on the 26-year old Murphy in free agency, signing him to a one-year, minimum salary contract of $715,000, hoping he will add some sizzle to a receiving corps that, when intact, has plenty of firepower. At 6-foot-2 and 200 pounds, Murphy has the requisite size, but it’s what he can do with his legs that intrigues the Giants.

Murphy flashed his great speed last week (4.34 in the 40-yard dash coming out of college) in his first organized team activity practice with the Giants, running past cornerback Corey Webster for what turned into a 50-yard reception on a perfectly-lofted pass from Eli Manning.

The Giants are not shy about cutting Manning loose with a down-the-field passing attack and he has been greatly effective, even though the speed element has often been missing. Hakeem Nicks is quicker with the ball than without it and Victor Cruz, still unsigned, has extremely crisp moves and good, but not exceptional speed.

There is no pure burner among the other receivers. Rueben Randle is a big target who can get down the field but won’t run by many defensive backs. Jerrel Jernigan is supposed to be a speed threat but is only 5-foot-8 with short strides and thus far hasn’t shown an ability to break a play open. Newly-resigned Ramses Barden is huge and definitely not fleet afoot.