Lockette was injured Sunday in Seattle's 13-12 win over Dallas during a punt return when he was hit by Heath and knocked out. He laid motionless for several minutes and was eventually strapped to a backboard and taken off the field.
Heath was penalized for an illegal blindside block on the play, but the league ruled Friday that it didn't warrant an additional fine.
The hit drew the ire of some Seahawks, with defensive lineman Michael Bennett calling the Cowboys and coach Jason Garrett "classless."
Asked whether the NFL's decision not to fine Heath makes it seem like officials erred by calling a penalty during the game, Garrett said, "Yeah. Trust me: He's as pure as it comes in terms of a football player -- his work ethic every day, wanting to play the right way and play at a high level. So certainly he did not intend to hurt anybody on that play. He wants to play the game with the right level of intensity and play the right way. I think we suspected that he wouldn't get fined because of how that hit came out. But he wants to play the game the right way."
Lockette was released from the hospital Thursday. He will not play again this season.
Bennett, meanwhile, was fined $20,000 for his late hit on Dallas quarterback Matt Cassel.
Information from ESPN.com Cowboys reporter Todd Archer and The Associated Press was used in this report.