Maynor has always had a better reputation than his numbers suggested. He's never posted a PER above 12 and hasn't even posted a true shooting percentage above 50 over a full season. He's an excellent passer, but isn't much of a scorer and has not shown much improvement since playing well as a rookie as Russell Westbrook's backup. Fans and coaches value him because he is unselfish and cerebral, which is often a contrast to the player he's backing up.
There is definitely some upside here, to be fair. Maynor fell out of Oklahoma City's rotation after struggling to return from a torn ACL suffered in January of 2012, but started to rediscover his game once he was dealt to Portland. He played a lot behind and with Damian Lillard (357 minutes, to be exact) and started to show some of the slick passing and quickness he displayed as a rookie. He also hit 38 percent of his three-pointers, which is an encouraging sign because he has to demonstrate some scoring ability if he wants to stick. His defense was poor, but that should improve with fewer minutes alongside another smaller guard and one more year removed from ACL surgery.