Day said that's the phrase defensive coordinator Brian VanGorder uses for a player who applies quarterback pressure but doesn't get a sack, or almost tackles someone in the backfield but helps another player make a big play. VanGorder talked in the preseason about how those plays can still have an impact.
Day, though, doesn't want to be that kind of player because those aren't the players who get praise from VanGorder.
''He recognizes it, but he doesn't give you credit,'' Day said. ''We don't accept almost guys.''
VanGorder preaches that ''sacks get stacks,'' Day said, referring to the money players will receive when they get drafted into the NFL.
Day doesn't have any sacks yet this season, but he is making an impact on the young defense of the ninth-ranked Fighting Irish (4-0) that was a concern before the season. It heads into Saturday's game against No. 14 Stanford ranked fourth in the nation in points allowed per game and 38th in total defense.
Day went from being a sidekick last season to defensive linemen Louis Nix III and Stephon Tuitt, who are in the NFL now, to being the leader on a line that is giving up just 108 yards a game rushing. Day was named a captain despite being a junior, leading mostly by example and speaking up in certain moments.
That's all right with coach Brian Kelly.
''Vocal to me is that he's not afraid to say something to somebody else about not living up to the standards that they need to - whatever they are,'' Kelly said. ''He's vocal up to the point he'll hold others accountable. That's great leadership to me.''
Day is easy to spot on the field with his high motor and dreadlocks down to his shoulders. He is fourth on the team in tackles with 19, and is second on the team in tackles for loss with 3.5. At 6-foot-2, he's the shortest starting defensive lineman for the Irish, but Kelly said he uses his quickness to overcome any height shortcomings.
''Whether he's 6-3, or 6-1, or 6-2, his skill set overcomes any lack of length at that position,'' Kelly said.
Two weeks into the season, Kelly had said Day hit a ''cliff'' after 50 plays, where his effectiveness dropped off. Kelly this week said that's no longer the case, praising how hard Day was going at the end of the win over Syracuse.
''I thought that singularly was a moment where he separated himself from everybody in terms of his effort and intensity,'' Kelly said. ''Late in the fourth quarter, we are up a couple of scores and he's out there just playing at 110 percent. That's the mark of a potentially great player.''
He believes this year's defense has the potential to be as good as the 2012 squad that led the Irish to the national title game.
''We still have so much room to grow. It's crazy how far we have come and how much we can still go. But I can see this defense turning out to be a great one,'' he said.
Day is looking forward to playing against the Cardinal because he knows it is going to be physical.
''It's brawn vs. brawn. We think we're the powerhouse. They think they're a powerhouse. We're going to find out Saturday,'' he said.