Harper, a 10-year NFL veteran safety who played against Newton for three seasons in New Orleans and alongside him the last two in Carolina, said he's amazed at the strides the Panthers' fifth-year quarterback has taken this season.
Losing Benjamin has forced Newton to do a better job of going through his progressions and make better decisions in the pocket, Harper said.
''It's almost like when you take someone's blankie away,'' Harper said. ''When it's taken away, you have to adjust. You have to grow up and do some other things to find your comfort zone. I think Kelvin's injury has done that.''
Harper said Benjamin was Newton's security blanket.
''I think it's opened Cam's eyes,'' Harper said. ''He's not locked in on one guy.''
Ten different receivers have caught five or more passes this season from Newton.
Newton didn't want to address his play without Benjamin, saying the injury to his close friend is too fresh in his mind.
He did say his approach has been to be ''aggressively patient.''
There was plenty of questions about how Newton would fare after losing the 6-foot-5, 245-pound Benjamin, who caught 73 passes for 1,003 yards and nine touchdowns last season.
But with a group of wide receivers that includes unheralded Ted Ginn Jr., Corey Brown, Devin Funchess and Brenton Bersin, Newton is excelling. He has relied heavily on Pro Bowl tight end, who leads the team with 374 yards receiving on 24 receptions.
He has a quarterback rating of 83.2, the highest mark of his career and the Panthers are 5-0 entering Sunday night's game against the Philadelphia Eagles.
''He's spreading the ball around and there are no real reads you can get on him,'' Panthers coach Ron Rivera said. ''That's beneficial. I do think (Benjamin's injury) has helped him to a degree. I know if Cam was doing what he is now and had Kelvin Benjamin out there too, who knows where we would be or what our potential could be.''
Newton struggled last season against the Eagles. He threw three interceptions and was sacked nine times in a deflating 45-21 loss.
But Eagles coach Chip Kelly said he sees a different Newton while watching game film this year.
''He is playing within their system and he is making really clutch plays at a clutch point in time,'' Kelly said. ''You look at that fourth quarter against the Seahawks last week and finding Greg (Olsen) and understanding coverages. He is throwing the ball really well right now. He is a complete quarterback and that is the thing that is scary - he can beat you with his arm and with his legs.''
Newton has 27 career games in which he has at least one touchdown rushing and passing in a game.
Only Steve Young, with 31, has more.
''He is obviously a legitimate dual-threat quarterback - and he is just so big,'' Kelly said. ''He is different than any other dual-threat that is tough to kind of corral, a Russell Wilson. Russell presents a whole different set of issues but with Cam, you may have him and hit him but he isn't going down and then he explodes out of there and you better have somebody being on top of him to contain him.''
Panthers offensive coordinator Mike Shula said Newton has grown in other ways, too.
He said toward the end of last season Newton began having more input in the team's offensive game plan.
AP NFL websites: http://www.pro32.ap.org and http://www.twitter.com/AP-NFL