BOSTON — 1B/3B Richie Shaffer has slugged his way to the big leagues.The Rays said they expect to call up Shaffer, their 2012 top draft pick who has hit 23 homers this season between Double-A Montgomery and Triple-A Durham, to make his debut tonight against the White Sox.Shaffer was removed from the Bulls game in the seventh inning Sunday, getting word of his pending promotion and hugs from teammates."I can't even begin to describe the feeling," he told the Tampa Bay Times from Durham. "It hasn't really set in. Right now, I'm actually under control a little bit. It probably will really hit me when I get on the plane (today)."Shaffer, 24, will take the roster spot opened by LHP Matt Moore 's demotion to Triple A, giving the Rays another right-handed bat as they face three straight lefties in Chicago. He can start ahead of lefty James Loney at first and provide a break if needed for 3B Evan Longoria , who was hit a few days ago on his sore left wrist. Shaffer has also done work in rightfield and was to make his debut there this week in Durham.Coming off a disappointing 2014 season, Shaffer worked out vigorously to add 20-25 pounds of muscle. After opening this season back at Montgomery, he excelled after a late May promotion to Durham, hitting .264 with 16 homers, 32 RBIs and a .954 OPS in 55 games, though cooling lately."Here's a guy with a plus tool in his power, the ability to drive in runs via the home run and hit the ball in the gaps," Durham manager Jared Sandberg said. "With his bat speed, he can do that."Shaffer was selected to the All-Star Futures Game and said in Cincinnati he was trying not to think too much about a promotion but was confident he could handle the opportunity if he got it."I'm excited," he said Sunday night. "But I'm not going to try to do anything different than the way I've played the game of baseball my whole life."The news capped a long day for Shaffer, who at 5 a.m. drove teammate Mikie Mahtook to the Raleigh-Durham airport so he could rejoin the Rays in Boston. MOORE POSITIVE: Moore is taking his demotion to Durham as step back to get headed in the right direction."I'm looking at this as an opportunity for me," Moore said via text message. "It gives me a chance to get my innings in, find my rhythm and regain my focus on what I have to do to get back and help the team."That's the most important thing, getting back to where I can contribute."The Rays made the decision after Moore's rough Saturday outing, his sixth since returning from April 2014 Tommy John surgery.The move won't be official until today for procedural reasons, likely that Moore has to clear optional waivers, which are required if more than three years have passed since a player was first called up.Manager Kevin Cash said there is no set time for how long Moore will stay in Durham. Taking advantage of several off days, the Rays are planning to go with a four-man rotation for now, which could take them through Aug. 17 or, with one bullpen day or spot start, Aug. 22 without needing a fifth starter. OUTFIELD WOES: With OF Steven Souza Jr . expected to miss 4-6 weeks due to the fracture in his left hand, the Rays plan to mix and match in filling out leftfield and rightfield.Without David DeJesus , who was traded to the Angels last week, that means more time for Brandon Guyer and Mahtook, who was called up Friday, sent back to Durham on Saturday, then called back up. John Jaso and Grady Sizemore also will get time.Souza, hitting .214 but leading the Rays with 15 homers, flew back to Tampa on Sunday and will see team hand specialist Dr. Doug Carlan today. "Obviously not an ideal thing for us or for him because his at-bats are crucial right now," Cash said. MISCELLANY: The Rays logged their 20th come-from-behind win. … OF Desmond Jennings (knee), 1-for-2 Saturday in his second rehab game for Durham, was off Sunday. … LHP Drew Smyly is likely to pitch for Durham Wednesday when he makes his third rehab start. … Temperatures in Chicago hit 100 during Sunday's game. … Sizemore turned 33 Sunday.