To fill the gaping holes in their wide receiver depth, the Giants on Saturday held a tryout and signed T.J. Jones and Amba Etta-Tawo.

Jones, 27, was with the Lions the past four years and has 64 career receptions for 814 yards and four touchdowns. Etta-Tawo was on the Giants practice squad the past two seasons.

Clearly, the duo adds depth, as the numbers for training camp were dangerously thin at the receiver position with the injuries to Sterling Shepard (thumb) and Corey Coleman (knee), and now a four-game suspension of Golden Tate, pending his appeal.

“At this point, it’s always a numbers game because you want to be able to practice,’’ coach Pat Shurmur said. “But you want to bring in guys that belong on an NFL roster and have a chance to compete.’’

Jones was a 2014 sixth-round draft pick by the Lions out of Notre Dame. His godfather is Raghib “Rocket’’ Ismail, the former Notre Dame star receiver and kick returner.

To make room on the roster, Coleman was placed on injured reserve and kicker Joey Slye was waived.

Shepard said he knew right away he had done something serious to his left thumb when he reached down to secure the football on Friday.

“I knew right away I broke it,’’ he said. “I broke this thumb before so I knew what it felt like.’’

In fact, this is the third time Shepard broke his left thumb — the first two times came in high school. This fracture is to the tip of the finger, which is less severe.

“It’s the best case,’’ he said. “I was pretty relieved. Now I give myself a shot to be able to play week one. Also I give myself the opportunity to get out there and catch the ball, hopefully in a couple of weeks.’’

The thumb will be wrapped for protection for at least two weeks. The Giants are confident Shepard will be ready for the Sept. 8 regular-season opener.

“I’m doing what they tell me to do, but I feel confident I’ll be able to make it,’’ Shepard said.

The Giants worked in full pads for the first time in camp, a day the linemen usually look forward to. “For sure,’’ DT B.J. Hill said. “In shorts, you can’t really do too much, but today’s the day, go out there and have a little bit of fun and a little bit of contact. I’m excited.’’ Hill showed that excitement by barking at the entire offense after the defensive pressure caused a false start penalty on G Will Hernandez.