There is no game plan for this. No tape to study or helpful hints available to be downloaded into his New York Giants-issued Microsoft Surface.

Finely tuned preparation, ensuring he can anticipate what to expect before it happens is the hallmark of Eli Manning’s NFL existence. Yet when an untimely death hit his radar and pierced his heart, Manning could not consult his notes to guide him. He leaned on his innermost feelings, traveled to Edgewood, Ky., on July 10 and attended the memorial service of former teammate Jared Lorenzen.

“Especially Jared,’’ Manning told The Post during a reflective break in the training camp grind. “We came in at the same time, competed against him in college, we were friends here for four seasons, won a Super Bowl, had so many good memories, in the meeting rooms and up in Albany at training camp. I went to the funeral and I saw his parents, to see his kids, it’s just sad. It’s just hard to kind of see that. That was tough.’’

This was Manning’s own time, his family time, two weeks before he reported to his 16th training camp. To many outside the building, Jared Lorenzen came and left the Giants’ orbit without much notice. Those who remember his four-year stay do so more for his size, which was outrageously large for a quarterback, than for the scraps of playing time he received. Yet Manning could not allow his erstwhile backup, removed from the team the past 12 years, to be memorialized and buried without paying his proper last respects.

Lorenzen died July 3 from heart and kidney complications. He struggled to keep his weight under control after he left the NFL following the 2007 season. His last game in a Giants uniform was Super Bowl XLII. Lorenzen was 38, the same age as Eli Manning.

Giants co-owner John Mara, adopting the “Once a Giant, always a Giant’’ mantra his father, team patriarch Wellington Mara, espoused, also made his way to Kentucky for the funeral, as did Zak DeOssie, the longtime long snapper, and Tim Slaman, the team’s assistant equipment manager.

Lorenzen, in two years as the No. 3 quarterback and two years as next in line behind Manning, appeared in four games. He completed four of his eight passes and twice was called on to use his 285-pound mass on quarterback sneaks. His career as the Hefty Lefty was less than nondescript, but his personality was as outsized as his body, as was his popularity.

“We were kids when we were playing together, we won some games here, but we were friends, first and foremost,’’ said DeOssie, 35, entering his 13th season with the Giants. “We obtained a dream together and … I don’t know … once you played together you are always friends for life. No matter how long you played together on the same team. Especially when you win a Super Bowl together. We wanted to be there for him.

“He was a great teammate. Funny, prankster, witty, sharp guy. He was just a good person to be around. Always brought laughter into our lives.’’

Fifteen days after Lorenzen’s death, the Giants suffered another tragic loss when Mitch Petrus, an offensive lineman for three seasons (2010-2012) died at the age of 32 from heatstroke back home in Carlisle, Ark.

“It was heartbreaking to see two former players pass away at such young ages, especially two good guys like Jared and Mitch,’’ Mara said. “In Jared’s case, he leaves behind two children. Both were very popular guys in our building and donated a considerable amount of time doing charitable and community work.’’

Seeing two former Giants pass away so young reminded Mara of a difficult stretch from 1979 to 1986, when Troy Archer, 24, died in a car accident, Doug Kotar, 32, died from a brain tumor and John Tuggle, 25, died from cancer.

“All good guys who died way too young,’’ Mara said.

The careers of Lorenzen and Petrus intersected with two of the greatest moments in franchise history, leaving both with Super Bowl rings and the bonds that championships forge. A teammate of Petrus’ on the Super Bowl XLVI team, safety Tyler Sash, was found dead in September 2015 at the age of 27 at his home in Oskaloosa, Iowa — his death caused by a combination of drugs. Sash had been suffering from the aftereffects of head trauma-induced CTE.

Petrus, a 2010 fifth-round draft pick, was an energetic, muscular lineman who played in a rock band and had an ebullient way about him.

“Loved life,’’ DeOssie said. “Would run through a wall for anyone on this team and he loved football. Great attitude. You knew you were always going to have a fun conversation with Mitch at the lunch table.’’

“A guy who won a championship here,’’ Manning said. “A member of that offensive line group, great energy, character guy. I read some articles on him and saw some videos, he was calling high school football games, was kind of bringing that same energy and enthusiasm so I was happy he found something he seemed to love. Just feel for the families of these two guys, great guys, great teammates, died too young.’’

Manning kept up with Lorenzen and last saw him in the summer of 2015 when the Giants held joint practices with the Bengals not far from Lorenzen’s home. Manning lost touch the past couple of years, but grew alarmed hearing reports and seeing pictures of his former backup weighing as much as 500 pounds. Lorenzen briefly shed some weight as part of a documentary called “The Jared Lorenzen Project’’ that became a subject on an ESPN E:60 feature.

“I talked to him and sent him a text, told him I was proud of him for doing that,’’ Manning said. “I did some interviews promoting that and tried to keep encouraging him with that. Then all of a sudden you didn’t hear about that for a while and didn’t know how it was going.’’

When Manning arrived for Lorenzen’s memorial service, he made sure he was dropped off at a private entrance, away from an area where media gathered seeking comments. This was a personal, private deal for Manning and it is not lost on him that he is the same age Lorenzen was at the time of his death.

Manning arrived at this year’s camp reminded almost daily of his advanced age as an NFL quarterback, with his eventual replacement, Daniel Jones, 22, already on the roster. Seeing a former teammate buried has a way of altering perspective when it comes to age and youth.

“I never consider myself old,’’ Manning said. “I know in the football world it’s on the latter parts of it. I think it does make you just appreciate being here, appreciate being at a training camp still, being part of a team, being a part of this and having great teammates around me.

“Also yeah, to just keep enjoying life and enjoying the people that are in my life and surrounded with and enjoy their company.’’