Tim McGraw Honors Late Father on His Birthday

Tim McGraw paid tribute to his late father, former MLB player Tug McGraw, on what would have been Tug's 76th birthday on Sunday, posting a video compilation in honor of his dad. "Happy Birthday Tugger! He would’ve been 76 today," McGraw's caption read. "We miss his nuttiness!" He ended the message with his dad's catchphrase, adding the hashtag #yagottabelieve.

The montage, set to McGraw's hit "Live Like You Were Dying," included shots of Tug playing baseball and photos of the father-son duo. There was also a magazine article, and the first shot of the video was a Country Weekly cover of McGraw and Tug with a headline that read, "Tug and Tim McGraw: After 18 Years Apart, Father and Son Are Together Again." McGraw was born to Betty D'Agostino, who had a brief relationship with Tug in 1966. After becoming pregnant, D'Agostino broke off contact with Tug and moved to Louisiana, where her son was born.

View this post on Instagram

A post shared by Tim McGraw (@thetimmcgraw) on

Until he was 11 years old, McGraw believed that his stepfather, Horace Smith, was his father, but discovered the truth after he found his birth certificate. The two met for the first time at the Houston Astrodome, and Tug denied paternity for seven years until McGraw was 18.

"It changed what I thought I could do with my life coming from the circumstances I came from," McGraw told Today last year of discovering his biological father's identity. "I felt like when I found that out, you know, he’s a professional baseball player who’s successful, to me, it made me think that blood is in my veins, so that ability is in there. So I found sort of that grit inside me that he must have had in order to succeed at what he did. And it changed what I thought I could make out of my life."

Tug died in January 2004 at age 59 after a battle with brain cancer. To honor his dad, McGraw started the Tug McGraw Foundation, which aims to enhance the quality of life for those with "neurological brain conditions such as brain tumors, traumatic brain injury, and post-traumatic stress disorder."