The Rockies (38-66) have lost six of their last seven games. Friday night was the 28th time they've lost despite scoring four or more runs.
Facing his former team, Sanchez didn't allow close to the damage relief pitchers Mike Ekstrom, Matt Reynolds and Carlos Torres did -- a collective 13 runs were scored against the trio in the final three innings -- but Sanchez's short start forced the bullpen into early and prolonged work.
"My first two innings weren't quick," Sanchez said. "I threw a lot of pitches in the first one, and we have a pitch limit, so that's why I didn't go deep."
The Rockies didn't help Sanchez much on defense -- rookie shortstop Josh Rutledge booted a potential double-play ball that resulted in an unearned run -- or at the plate, managing just five hits against Giants starter Ryan Vogelsong, who put on a clinic before giving up four runs in the seventh inning.
Vogelsong (9-5) kept his pitches low in the zone, throwing 63 percent for strikes and not allowing a baserunner until the fourth. With the bags full for the Rockies, Vogelsong got Jordan Pacheco to ground into an inning-ending 5-4-3 double play.
Sanchez (0-3 with the Rockies, 1-9 overall) could only hope for such timing. His first pitch of the game was drilled by Angel Pagan for a single, then an errant pitch allowed Pagan to advance to second. Ryan Theriot drove Pagan in with a single, Rutledge couldn't come up with a spinning grounder and Buster Posey was issued a walk.
Hunter Pence grounded out to plate Theriot and make the score 2-0.
After another hit and wild pitch in the third inning, Sanchez was pulled. His one earned run allowed was Sanchez's lowest total with the Rockies, but so was his three innings pitched. Sanchez threw more balls (34) than strikes (33).
Adam Ottavino relieved Sanchez and allowed one run in three innings. He allowed two hits and struck out four, but Ekstrom gave up four runs on three hits in the seventh.
The Rockies chased Vogelsong with a four-run rally a half-inning later to pull the Rockies back within three. Fowler led off the inning with a triple -- to give him 50, the most in franchise history -- and scored on a Carlos Gonzalez sac fly.
Pacheco roped a double, the sixth in his last four games, and Todd Helton followed with another double. Rookie catcher Wilin Rosario then snuck his 18th homer of the season just inside the left-field foul pole.
"Offensively we did a very nice job with the four-run offensive inning, but unfortunately we were down by seven at the time," Tracy said.
The three-run deficit quickly grew, however, when Reynolds allowed six runs in the eighth and Torres allowed three more in the ninth, while the Rockies' bats went back into hiding.
"We're gonna have days like this," said rookie shortstop Josh Rutledge, who was kept off the basepaths for just the third time since his July 13 callup. "There's gonna be days where we don't hit and they pitch well and days when we do hit and they don't pitch as well as they want. But it's baseball, you can't do anything about it."
Colorado's bullpen entered the game with a collective ERA of 4.09. After the final out had finally been recorded, that number had swelled to 4.31.
The Rockies acquired Sanchez from Kansas City on July 20 with the hope he could be an improvement over Jeremy Guthrie, who was 3-9 with a 6.35 ERA in 15 starts.
After three starts with the Rockies, Sanchez has put up numbers worse than Guthrie's: 12 earned runs in 11 1/3 innings of work with a 1-to-1 walk-to-strikeout ratio, all culminating in a 8.07 ERA.
"I don't feel like there was anything wrong, I just have to get out there and keep being aggressive," Sanchez said. "I have to make quality pitches."
The left-hander hasn't been right since left bicep tendinitis kept him out for most of May and the first two weeks of June. In six starts with the Royals after returning June 13 through his last outing with them on July 16, Sanchez went 0-4 with a 8.68 ERA while opposing hitters batted .342 against him.
"You always wonder when you catch guys what it would be like to face them," said Posey, who caught Sanchez in 2010. "His stuff's still pretty good. He was struggling with his command a little bit."
With Christian Friedrich revealing after the game that he will likely miss the rest of the year with a stress fracture in his lower back, the Rockies are suddenly swimming in pitching problems: Juan Nicasio suffered a season-ending knee injury in June, Jorge De La Rosa hasn't pitched this year and Jhoulys Chacin is still two rehab assignments away from joining the club.
But Tracy wouldn't commit, one way or the other, to what they plan to do with Sanchez, who is out of Minor League options.
"I won't talk about that tonight," Tracy said.