McGrath -- who tossed a perfect seventh inning in the Padres' 7-1 loss to Pittsburgh on Sunday -- learned he was headed to San Diego late Wednesday night.
Then he waited. And he waited some more. In fact, he waited so long, his parents canceled their flight home Saturday. (Fortunately, his father, James McGrath, worked for American Airlines and has plenty of miles to use.)
"Every time the [bullpen] phone was ringing, my stomach was dropping a little bit," McGrath said. "The anticipation kept building and building. But it's good to get that one out of the way."
McGrath wasted no time recording his first Major League strikeout. He got Bucs starter Gerrit Cole looking on three pitches. Then he fooled Starling Marte on a changeup, inducing a weak pop to center field. McGrath punctuated the inning with a strikeout of Max Moroff on a nasty changeup.
One day before McGrath turns 25, it was quite the birthday present.
"It's everything you really dream of," McGrath said. "A lot of nerves. You look around with the crowd, this place is almost full, and it's a really cool feeling."
McGrath's parents and his fiancee had been in town since Thursday morning. They met him in the tunnel outside the Padres clubhouse following the game.
James McGrath harkened back to the summer following Kyle's freshman year of college at Eastern Kentucky. Kyle informed his dad he'd be transferring to Louisville, where he planned to walk on. At such a prominent Division I program, James McGrath warned Kyle, "You realize you may never get to play baseball again."
"He's finally proved everything that so many people thought he could never do," said an emotional James McGrath. "It's euphoric, that's for sure."
McGrath's funky over-the-top delivery has played no small part in his success. He has posted a 2.66 ERA at Double-A San Antonio this season and owns a 1.61 mark in four Minor League seasons.
For one game at least, that success translated to the big league level.
"It was awesome," McGrath said. "I was pretty nervous going into it. But now that I've got one under my belt, it's a great feeling."