#Giants have their own issues to worry about versus ailing 49ers

Do you believe in this theory? It is not who you play, but when you play them.

If this is true, the Giants have a fighting chance Sunday against the defending NFC champion 49ers.

At full strength, the talent level is a mismatch, but the 49ers are not at full strength. Far from it. If the list of depletions featured only quarterback Jimmy Garoppolo, who has a high ankle sprain and will be replaced by backup Nick Mullens, it might be more of an annoyance than anything else for a team that comes into MetLife Stadium concerned with more than nasty turf.

In a misleading way, the Giants are healthy, with just two reserve players on their injury report. Misleading, because two key players, Saquon Barkley (out for the season) and Sterling Shepard (out at least three games) are on injured reserve and thus not on the report. The Giants, taking the field without Barkley, cannot be considered healthy in any way, shape or form.

The Giants are not whole. The 49ers are battered. They will be without 10 projected starters or prominent players, five apiece on each side of the ball. It’s a ridiculously long list and represents 40 percent of the team’s salary cap allotment.

On defense, no Nick Bosa — perhaps the defensive equivalent of Barkley to the Giants. No Solomon Thomas. No Dee Ford. No Richard Sherman. No Dre Greenlaw. On offense, no Garoppolo. No Raheem Mostert and no Tevin Coleman in the backfield, part of the injury conveyor belt that caused coach Kyle Shanahan and some of his players to rip the newly laid turf at MetLife Stadium as unsafe. No Tavon Austin or Deebo Samuel at receiver. No George Kittle, the game-changing tight end who hurt his knee in the season opener against the Cardinals.

“Anytime you have injuries, it always affects your guys somewhat, especially when you lose some big names like we did,’’ Shanahan said. “But that doesn’t mean we’re a bad team. We’ve got lots of good people on this team, we had lost a ton of guys last year and were able to persevere and get through it.’’

That is the Niners’ problem. The Giants have enough trouble of their own. They face 14 games without Barkley and understand he cannot be replaced. They signed veteran Devonta Freeman, and in time he might be able to rekindle some of his form from his best days with the Falcons. Or perhaps he might not. For now, Dion Lewis and Wayne Gallman (remember him?) will have to carry the load.

To further burden Daniel Jones with extra pressure to produce in the passing game is troublesome, considering the Giants go into Week 3 as the NFL’s lowest-scoring team. Jones needs play-action to be at his best, and that means some semblance of a running game. Without it, the Giants are sunk, no matter how many times Jones wriggles free from pressure and is able to slip the ball out to an alert teammate for a first down.

The Giants played a solid first half against the Steelers and outscored the Bears 13-0 in the second half in Chicago. It adds up to 0-2 and proves the Giants were not yet ready to win.

“I think a team will win when it executes on the field for 60 minutes the way it needs to,’’ first-year coach Joe Judge said. “To kind of sum that up, you can summarize that to say when you’re ready you execute for 60 minutes. But I’m pleased with the improvement I’m seeing from our team. We just need to string it together on the field and let these guys to ahead get some tangible results for the work they’re putting in.’’