Giants defensive ends Jason Pierre-Paul and Olivier Vernon missed a combined three defensive snaps on Monday Night Football against the Cincinnati Bengals. They were on the field for 113 of a possible 116 defensive snaps, which typifies a season in which they have been nearly ever-present for the Giants in an era where top pass-rushers have become more situational players.

Von Miller leads the league in total pressures, with 54; he has played 79.7 percent of Denver’s defensive snaps, actually up on the 75.6 percent he saw a season ago. JPP has played 95.9 percent; Vernon, 91.5.

Pierre-Paul and Vernon lead all NFL edge defenders this season in snaps played. They are the only two players to have broken 600 defensive snaps (634 and 605, respectively), while only 15 other players have even topped 500 snaps. The league used to be full of defensive players that never left the field, but when it comes to defensive linemen in particular, rotation has become king.

Eagles DE Brandon Graham is currently tied for the No. 1 ranking in PFF’s edge defender grades, with a score of 90.3 (tied with Miller and Khalil Mack). He has 50 total pressures on the season, but has been on the field for only 435 snaps as the Eagles rotate him to keep him fresh throughout the game. Graham has been on the field almost 200 fewer snaps than Pierre-Paul, but has nine more pressures.

While it may seem that being on the field longer increases the chances that a player will generate pressure, simply by ramping up the opportunities to rush the passer; what we often see, however, are diminishing returns, where a defender is playing too much to remain at 100 percent throughout the game.

Both Pierre-Paul and Vernon are playing well this season. They each rank inside the PFF's top 20 edge defender grades, and though they may not be among the league’s sack leaders, each has amassed an impressive amount of pressure. As a pair, they have 83 total QB pressures, and are only separated by one (41 for JPP, 42 for Vernon), while Pierre-Paul has added six batted passes to his stat sheet on pass-rushing plays. Both players rank among the league’s top 10 edge defenders in terms of total pressure, but at what point would the team be better off giving them some recovery time in-game?

The first issue is that, in order to spell a player, you need somebody capable of taking those snaps and not proving to be a liability. So far the Giants don’t have anybody that fits that billing. The team spent a third-round draft pick a year ago on Owamagbe Odighizuwa, but he has earned nothing but negative grades in his time in the NFL, even if that time totals 236 defensive snaps of action.

In 94 pass-rushing snaps this season, Odighizuwa has only recorded four total QB pressures, or pressure once every 23.5 attempts. JPP has generated pressure once every 9.6 rushes, and Vernon once every 9.2, so to take either off the field and replace him represents a major downturn in production that is unlikely to be offset by any potential boost in their yield over the smaller number of snaps they are playing.

Romeo Okwara and Kerry Wynn are the only other defensive ends to get snaps for the Giants so far this season, and in 133 combined pass-rushes, they have done only marginally better than Odighizuwa, with eight total pressures between them (one in every 16.6 attempts).

The Giants may well be in a situation where they want to spell Pierre-Paul and Vernon, but simply don’t trust any of the backups to get the job done in their place, however limited the role is. Even in run defense, the story is much the same. Pierre-Paul, Vernon, and DT Damon Harrison are the only New York defensive linemen to have strong grades against the run, so the team can’t even try and tilt the balance of their snaps by giving some of the obvious run situations to other players.

Pierre-Paul is on pace to play 1,128 defensive snaps this season, and Vernon 1,075. Those would both be among the highest figures PFF has seen from an edge defender over the past decade—JPP's would be the third-highest figure among all edge defenders over that span, in fact. Only Connor Barwin and Chandler Jones in 2013 played more snaps than that projected total, and neither had a strong pass-rushing grade by the end of it.

The Giants have one of the league’s better pass-rush duos, but they run a very real risk of seeing their effectiveness diminish over the second half of the season, unless they can figure out a way of dialing back on their workload.