One of the additions will be first baseman Mike Carp, who is currently on a rehab assignment as he recovers from a strained groin muscle. Carp felt some tightness in the leg during a swing and was taken out of Tuesday's game and sat out Wednesday in Las Vegas, but is expected to play Thursday.
The Rainiers also have a number of players who spent time with the Mariners at various points this season, as well as some prospects who will get their first look.
"There are a few guys who were here quite a bit of the year we want to get back up, and a few of the younger guys we want to put our eyes on, even if they're not playing a great deal, just to have them up here in this environment," Wedge said. "I think that's healthy and part of the progression, which is important."
Wedge wasn't naming names, but among the current Rainiers players who've been with Seattle at times this season are outfielders Casper Wells and Carlos Peguero, infielder Alex Liddi, reliever Shawn Kelley and starters Erasmo Ramirez and Hector Noesi.
Danny Hultzen, the first-round Draft pick in 2011, is the highest-profile prospect with the Rainiers, but he's struggled down the stretch and saw his record fall to 1-4 with a 6.09 ERA after giving up six hits, six runs and five walks in 2 1/3 innings Wednesday in Las Vegas.
"It's his first year of pro ball. He goes right to Double-A and did great," Wedge said. "Triple-A is a little different level. We didn't expect him just to run straight through everything. It's just too hard. I know he's learning a great deal down there.
"It's toward the end of the year and I'm sure he's feeling it a little bit with a long year, but he's had a lot of success, he's impressed a lot of people. Sometimes you learn more from those tough outings than anything else. With his mindset and maturity level, he's going to be fine."