The position battles to watch for in Giants’ preseason opener vs. Lions

Here’s what to look for in the Giants’ first preseason game against the Lions on Thursday

Cornering the market

There is a gaping hole at a key starting spot on defense: the perimeter cornerback opposite Deonte Banks.

The Giants did not address this in free agency or the draft — third-round pick Dru Phillips looks to be winning the slot corner job.

Cor’Dale Flott in camp has lined up with the first team, and his results have been up and down.

Nick McCloud is versatile enough to move around the secondary and is challenging Flott on the outside.

Tightrope tight ends

Rookie Theo Johnson is impossible to miss, at an imposing 6-foot-6 and 264 pounds.

He missed time early in camp but proceeded to impress as soon as he got into the action.

Will he be ready for a heavy load as a starter in his first year?

How Johnson and Daniel Bellinger will be utilized together will be interesting viewing.

Safety first

The expectation when Tyler Nubin was selected in the second round of the draft was for him to start at safety alongside Jason Pinnock.

A calf injury cost Nubin the first week of training camp.

Dane Belton, entering his third year, stepped in and looked as if he belonged with the first-team defense. Nubin has ground to make up.