Top prospects Tacoma-bound

What more do Danny Hultzen and Nick Franklin have to prove in Double-A?

The answer: nothing.

The Mariners’ two prized prospects will be moving up from the Jackson Generals to join the Triple-A Tacoma Rainiers, a source within the Mariners’ front office confirmed Tuesday.

The move likely will be announced today or Thursday. The Mariners wanted to allow Hultzen and Franklin to play in the Southern League All-Star Game on Tuesday as a reward for their successful first halves.

The left-handed Hultzen started the game and pitched one scoreless inning, getting one strikeout. Franklin went 0-for-2 with a walk.

Hultzen, the Mariners’ top pitching prospect and the second overall pick of the 2011 draft, is 8-3 with a miniscule 1.19 ERA in his first season of professional baseball. He is riding a streak of 262/3 scorless innings pitched and has allowed only five earned runs in his past 71 innings. Opponents are hitting just .148 against him during that span.

For the season, he has struck out 79 batters, allowed 38 hits and walked 32 in 75 innings.

Franklin is widely considered to be the Mariners’ shortstop of the future, possibly the opening day starter for next season. At just 21 years old, he has rocketed through the Mariners’ system since being drafted with the 27th overall pick in 2009.

He is hitting .322 (66-for-205) with a .394 on-base percentage and a .502 slugging percentage. He has 17 doubles, four triples, four homers and 26 RBI. He also has nine stolen bases in 11 attempts.

Franklin also is considered the best position-player prospect in the Mariners’ minor league organization.

He will join one-time top prospect Carlos Triunfel and veteran Luis Rodriguez as Tacoma’s shortstops. Franklin is expected to get plenty of time at shortstop for the Rainiers as well as some games at second base.

Tacoma is hosting the Reno Aces for games today, Thursday and Friday before traveling to Colorado Springs to face the Sky Sox.

MONTERO CATCHING BECAUSE HE’S HITTING

Jesus Montero started at catcher for the second straight night, and Mariners manager Eric Wedge made it clear that he’s in there because of his bat.

That’s not a knock against Montero’s catching. The young catcher is progressing defensively.

“He’s really impressing me with his catching,” Wedge said.

Unable to use a designated hitter because the game was played in a National League park, Wedge opted for offense over the experience of Miguel Olivo.

With a day game today following Tuesday’s night game, Montero is likely get the day off. But he is expected to be in the lineup Friday night in San Diego.

ON TAP

The Mariners will send left-hander Jason Vargas (7-6, 3.95 ERA) to the mound for the 12:40 p.m. start. Arizona will go with right-hander Trevor Cahill (5-5, 3.08 ERA). The game will be broadcast on Root Sports, and 1240-AM and 1030-AM.