He arrived in the Lancaster clubhouse from extended spring training on May 27, just hours before starting at second base and has hit hit safely in his first three games.
He entered Wednesday's important game with the High Desert Mavericks batting .353, but it wasn't Harrison's bat that helped propel the JetHawks to victory.
It was his arm.
Harrison's relay throw from right field in the eighth inning nailed the Mavericks' Ray Suplee at home to preserve the JetHawks' 6-5 victory and force a tie atop the California League's Southern Division standings.
"We practice it so much, it just comes natural," said the 19-year-old Harrison, who quickly deflected praise to the outfielder who started the relay, Jose Cruz Jr. "Without Jose, the whole situation wouldn't have happened."
Cruz, with Rancho Cucamonga's 6-1 loss at Stockton in the back of his mind, said: "They say defense wins championships, right?"
Maybe, Jose. The JetHawks and Quakes are both 31-28 and in first place with 11 games left in the first half.
Two of the players the JetHawks assumed would lead them to the Cal League playoffs stepped forward Wednesday night.
Shane Monahan and Cruz, Seattle's top two draft choices last year, combined for six hits (including four for Cruz) and drove in three runs in the heart of the JetHawks lineup.
Tom Szimanski struck out the side in the ninth for his sixth save, giving the win to Brett Hinchliffe, who improved to 5-5.
Lancaster scored three times in the sixth to take a 5-4 lead.
Cruz led off with a double and stole third base as Jesus Marquez struck out. Jason Cook drove Cruz home with a single up the middle.
After James Clifford lined out, Scot Sealy hit his seventh homer to straightaway center field to make it 5-4 and drove High Desert starter Matt Marenghi from the game.
"(Marenghi) threw me a changeup and left it up too well," said Sealy, who paused for a second at home plate before beginning his trot. "When you hit a ball that far you want to see where it lands."
The Mavericks' four-run rally in the fifth came with one out.
After Chris Kirgan popped out, extending Hinchliffe's string of retired batters to 11, Suplee doubled to left-center field.
Jason LeCronier single, Suplee moved to third and Bryan Bogle drew Hinchliffe's first walk of the game which loaded the bases.
Jesse Garcia, the No. 9 hitter in the High Desert lineup, watched two close strikes with a 3-0 count before taking a pitch just off the plate for a walk, driving in Suplee.
That run not only cut the Lancaster lead to 2-1, but it was the first run the Mavericks scored in the first 13 innings of the series.
Lancaster's 7-0 shutout Tuesday night was the first for High Desert at home this season.
Rolando Avila hit a two-run single to right field as the Mavericks took a 3-2 lead. They made it 4-2 on David Lamb's groundout.
The JetHawks took a 2-0 lead in the first before most of the paid attendance of 972 took their seats.
Marcus Sturdivant hit his team-leading 18th double of the season, went to third on a wild pitch and scored on Shane Monahan's RBI groundout.
Cruz made it 2-0 with a home run over the wall in right field, his fifth.