I agree he should retire.
Targeting him should be a fireable offense, because it will result in league sanctions against the team and coaches responsible.
The problem is saying “targeting” because that implies singling him out for tactics beyond those used normally. Normally players should play to the limit of what the rules allow. So targeting means going beyond what’s allowed by the rules.
Doing that in an attempt to injure a player should result in suspension and other sanctions. Any coach who directs players to do that should be fired for acting against team interests.