Mitchell Kilkenny had the shortest start of his career Thursday night, lasting only two-thirds of an inning in Grand Junction's 11-2 loss at Billings.
In the final game of the road trip, the Rockies managed only two runs on four hits and struck out 14 times, losing their sixth straight game. They went 1-6 on the trip.
It's Grand Junction's longest losing streak of the season and dropped the Rockies (26-28, 7-9) into third place behind Orem in the Pioneer League South Division with three weeks remaining in the season.
Grand Junction needs to either win the second half or finish second behind Ogden, which won the first-half title, to return to the Pioneer League playoffs.
They'll need to start getting quality pitching again, and the offense needs to catch fire again to make a playoff run, starting at home Saturday night against Orem, the first game of an eight-game homestand.
Against the Mustangs, who swept the series, Grand Junction couldn't do much offensively. Starter Omar Conoropo (5-0) allowed only two hits through the first five innings and struck out six.
Patrick Raby gave up one run, walking three and striking out three, over the next two innings, and Jeffry Nino struck out five over the final two innings, allowing one run on two hits.
Kilkenny gave up five runs on four hits, struck out one and hit two batters, leaving with two out in the first. Reniel Ozuna delivered a bases-loaded triple in the first, and a base hit got another run home.
After Kilkenny hit Valentin Martinez, he was lifted for Cayden Hatcher, who allowed the runners to move up on a wild pitch, then surrendered an RBI single to Reyny Reyes, putting GJ in a 5-0 hole.
The Rockies tried to jump-start the offense in the top of the first, with Julio Carreras leading off with a triple. Jack Yalowitz was hit by a pitch, but Christian Koss popped out in foul territory.
Carreras tried to steal home on the back end of a double steal, but was thrown out, and Yalowitz was thrown out trying to take third on the rundown to get Carreras, and Brenton Doyle struck out.
Down 8-0, the Rockies got on the board in the seventh when Reese Berberet scored on a wild pitch. Doyle singled to lead off the ninth and scored on Todd Isaacs' double.