DETROIT -- Al Avila gets the fan frustration, he said.

Even before the Red Sox posted three runs off Ryan Carpenter in his latest spot start and three each off Jose Cisnero and Austin Adams during the Tigers’ 9-6 loss on Friday night at Comerica Park, the Tigers' general manager said he understood the impatience. The rebuilding project that earned Avila a multi-year contract extension from Tigers chairman and CEO Christopher Ilitch on Friday has yielded little results with the big league club.

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“Right now, in the middle [of the process], it’s like the darkest hour,” said Avila, who wasn’t referring to the thunderstorm that delayed Friday’s game for just over two hours at the start of the sixth inning.

The brighter skies are in the farm system, where the Tigers believe they have the makings of a stingy rotation in time. But for the talent in the right arms of Casey Mize, Matt Manning, Alex Faedo and Beau Burrows, that time isn’t now. In the case of the first three, it probably isn’t this season at all.

Avila gets the impatience, especially in stretches like this, but he isn’t rushing the process.

“I think for the most part, when I talk to people in the streets, [read] some fan mail that I get, for the most part it’s been understanding of what we’re doing -- not liking it,” Avila said. “I don’t like it. You guys don’t like it. The guys that cover us on TV and radio, they don’t like it. But it’s a process that we have to go through. It’s a process that other teams have gone through.

“Kansas City, before they won the World Series, look at how many years it took them to get to that point. Houston, the same way. Chicago, the same way. San Diego, they’re still battling that. Philadelphia now is a playoff contender. We’re not unique to this situation or this process. What have to do is have the courage to see it through. And every day that I show up to work, I have to face that. And that’s what we’re doing.”

Carpenter’s start Friday, two days after former second-round pick Tyler Alexander made his Major League debut, was an example of the patience. Though Avila has laid down the gauntlet for Burrows, the Tigers’ sixth-ranked prospect by MLB Pipeline, and Kyle Funkhouser, Detroit’s 10th-ranked prospect, to join the rotation by summer’s end if they progress, that progress has ebbed and flowed.

Avila was at Triple-A Toledo earlier this week to watch both of them pitch for the Mud Hens. Funkhouser allowed more runs (seven) than he recorded outs (five), as he fought his mechanics. Burrows lasted five innings, but with four walks over five innings of two-run ball, the former first-round pick had trouble repeating his delivery, a challenge he has faced the last couple years.

Both missed valuable time with right shoulder inflammation. Both are showing why promotion for prospects is not simply a matter of graduation.

“You have to earn your way to the big leagues,” Toledo manager Doug Mientkiewicz said earlier this week. “You should have to perform first. I think we all understand that. It hasn’t gone the way, I don’t think, anyone wanted it to.”

Thus, back came Carpenter, who gave up 11 runs for the Mud Hens in one start last week and then racked up 11 strikeouts in six scoreless innings the next. He gave up three runs in his first three innings Friday against the Red Sox, including a two-run homer from Rafael Devers in a lefty-lefty matchup, then held Boston there before rain ended his night after five innings. The Tigers optioned Carpenter to Toledo following the game.

Friday would’ve been rookie left-hander Gregory Soto’s day to start, but Carpenter’s call-up and three games over the previous two days pushed Soto to the bullpen, where he pitched Friday’s seventh inning. That opens a spot start for Sunday’s series finale, the final game before the All-Star break.

Funkhouser or Burrows would be on turn, but need to develop. For this year, Mize, Manning and Faedo are not options. The anticipation that built in Chicago when the White Sox promoted Dylan Cease, 18th on MLB Pipeline’s Top 100, for his Major League debut Wednesday provided a preview of what the Tigers will face when their big names -- or even their mid-range prospects -- arrive. The downpour of defeats has only deepened the thirst.

“You don’t want to promote a guy just for the sake of publicity,” Avila said. “You want to promote guys for experience, and getting them ready for the following season, and to kind of give them a test to see what you’ve got. Case in point: Tyler Alexander is a good situation. We have to protect him [on the 40-man roster from the Rule 5 Draft] in the wintertime. It makes sense to bring him up now and see what he’s going to do for the next couple months. If he doesn’t do well, then you suffer through those months; that’s what rebuilding is. If he does very well, you feel good about it, and you feel good about next year. The same thing is true of other guys that we’re going to have to protect.”

Funkhouser and Burrows are in the same position, needing to be added to the 40-man roster by the offseason. The opportunity is there for them to take.

More decisions like this await, and more struggles as the already-young Tigers get younger. It’ll take more learning, and more patience. Avila now has the contract security to see it through, but it doesn’t make it any easier on him.

“A lot of people that I come across with, [they’re] like, ‘Man, I really feel for you. I wouldn’t want your job in 100 years,’” Avila said. “I really get a lot of that, because baseball people understand how tough this is, because you have to put up with all the scrutiny.”