After the Pirates dropped their ninth in a row, 6-4 to the White Sox on Tuesday, Huntington said Alvarez is expected to join the team for Wednesday night's game against Chicago.
Alvarez, the No. 2 pick in the June 2008 draft, remained at Triple-A Indianapolis as the interleague series opened -- even though there were hints last week that his arrival might be imminent.
"He's on his way here, and assuming he has no travel issues, we'll make it official [on Wednesday] -- and have a whole lot more to say about it," Huntington said. "Sorry I don't have a lot more to say."
Although Alvarez, 23, has significantly upgraded what previously was a weakness -- hitting left-handers -- Huntington said a few hours before the team's latest loss that there are areas that need improving before Alvarez is major league-ready.
Apparently, the Pirates changed their minds in only a few hours' time.
"He's not going to be an accomplished player in all areas when he comes up, but no player is," Huntington said. "We're looking forward to his arrival here in Pittsburgh, whether it's this week, next week or next month. It's going to happen here at some point, pending health and the continuation of his progress and development."
Alvarez is hitting .277 with 13 homers, 15 doubles and 53 RBIs at Indianapolis -- the kind of power the Pirates are lacking. He went hitless in three at-bats during a 4-1 loss at Scranton/Wilkes-Barre on Tuesday night.
"I'll be happy when it happens because we've envisioned this for a long time," manager John Russell said. "There will be days he struggles, but it will be a big boost for the ballclub."
Only one Pittsburgh hitter, Garrett Jones (10 homers), has more than six homers, and starting left fielder Lastings Milledge still hasn't homered this season. The Pirates rank last in the majors in runs scored.
Huntington is aware there will be tremendous pressure on Alvarez to immediately start carrying what possibly is the majors' weakest offense. That's a lot to ask of a player who is only two years removed from amateur baseball.
"We're going to be conservative about moving guys up, not only to the majors but from A-ball to Double-A. There's too many damaged prospects," Huntington said. "It's a tough balancing act. The game is littered with players that were rushed because teams were desperate. If a player's not ready, he's not ready. That's a foolish way to run an organization and a foolish way to run a business."
The Pirates understand he won't be a finished product.
"Is he ready to come up and face the best situational lefties in the game? He's probably not going to be ready for that for a year-plus," Huntington said. "Is he where he needs to be [defensively]? He's certainly getting closer every day."