EAST RUTHERFORD, N.J. -- It looks as though New York Giants wide receiver Victor Cruz won't play in Saturday night's preseason game against the Jaguars. Cruz was a "maybe" to begin with as the Giants continue to nurse him back from last year's devastating knee injury. But the fact that he developed a calf injury (in the other leg) this week moved him into the "probably not" column, per coach Tom Coughlin on Thursday.

Cruz still hopes to get into at least one of the final two preseason games -- Aug. 29 against the Jets or Sept. 3 in New England -- so he can work at real game speed prior to the Sept. 13 regular-season opener in Dallas. And while the Giants won't commit to putting him into one of those games, they really should try to do so.

To this point, Cruz's rebuilt knee has passed every test they've been able to give it. He works in practice, his straight-line speed looks fine and he catches the ball well. But training camp practice doesn't test you the way a game -- even a dreadful NFL preseason game -- tests you. In practice, Cruz doesn't experience scenarios in which he might have to suddenly and unexpectedly employ explosive moves, such as leaping for a ball. The question about Cruz's repaired patellar tendon isn't how fast it will allow him to run, it's how much power it will allow him to deliver when he needs to push off on his leg with violence and aggression.

And while Cruz can simulate that to some extent in a controlled practice environment, there's no way to know for sure whether it will be there when he really needs it. Practice reps are all designed. He knows the guy covering him isn't allowed to hit him. Most of the time, he knows whether to expect the ball. And the lack of real consequences makes it less important to really stress the joint the way he might have to in order to make a big touchdown catch against the Eagles in Week 6.

"You want to go out there in real-time action and get some good, solid work in with everyone else and everyone ready to go, but that’s not always the case," Cruz said Thursday. "I think these practices are pivotal in terms of getting everybody healthy, getting everybody out here understanding what we do in practice, because it’s such a tedious game with all these little nuances that you have to learn and know, especially with our offense. That’s the biggest thing for me, is that we’re focused in practice. Then I feel like the game stuff will come."

For Cruz, though, it matters a bit more. He's passed every test there is to pass in practice. But until we see him at game speed, and watch him execute high-level NFL athletic moves on his surgically repaired right knee, there's really no way we can assume he'll ever be back to full strength. Getting him into a preseason game is the only means the Giants have of figuring out whether they can count on him to be the player he once was. If he can't play in the preseason, then come Sept. 13 in Dallas everyone will still be wondering.