Ramirez, a veteran left-handed reliever, and Romine, a versatile infielder with a quality glove, have made appearances with the Angels this season.
"Ramirez out of the 'pen is a lefty who can get an out," Scioscia said. "Romine gives us versatility and depth at shortstop."
Navarro, a smooth defender with a left-handed bat, and the swift, athletic Moore, another left-handed option off the bench, will be making their Major League debuts.
"Moore is just a raw talent who's slowly putting it together," Scioscia said. "He can play all three outfield spots. He can run, and he's got a chance to put it together. He's a lefty who can drive the ball.
"Navarro is a terrific defensive first baseman. Efren doesn't have tools that are going to light your eyes up, but he's a baseball player."
Ramirez was 1-0 with a 9.00 ERA in seven appearances for the Angels. Romine, who has speed to go with his exceptional defense, appeared in five games with one hit in nine at-bats during his brief stay with the big club.
At Salt Lake in the hitter-friendly Pacific Coast League, Ramirez appeared in 45 games with a 3-2 record and 3.96 ERA. He has extensive Major League experience.
Romine, a natural shortstop who made the transition to third base at Salt Lake, batted .281 with 23 steals in 29 attempts.
Drafted by Angels in the 50th round in 2007 out of the University of Nevada Las Vegas, Navarro has been on fire late in the season, batting .424 since Aug. 12 with a .924 OPS. He's batting .317 with 36 doubles and a career-high 12 homers. A deft defender, he committed only three errors for a .998 fielding percentage.
Moore, a sixth-round pick in 2005 from Louisiana, leads the PCL with 18 triples, tying a Salt Lake franchise record. He has 21 steals, 24 doubles and 15 homers, slugging .545. He also has made consistent strides defensively in the outfield.
Not included among the first callups were Trevor Bell, Matt Palmer, Michael Kohn and Tyler Chatwood, pitchers with experience in the Majors. Another, Garrett Richards, is recovering from a groin injury and is an option when he's ready.
Chatwood, who is 6-9 with a 4.35 ERA in 23 starts for the Angels, has been refining his command at Salt Lake with two starts since his demotion on Aug. 18. Bell, 1-1 with a 3.38 ERA in 16 relief appearances for the Angels, could rejoin the bullpen. He has been starting at Salt Lake.
Kohn, who made 14 appearances for the Angels (0-1, 7.30) after an impressive 2010 rookie season with the Angels, has racked up impressive numbers at Salt Lake. Palmer (1-1, 5.74 in three Angels starts) has been inconsistent with the Bees as a starter. Yet another former Angels reliever, Francisco Rodriguez, is back throwing after a long bout with right shoulder tendinitis. He has made three relief appearances for Salt Lake.
Navarro is a product of Major League Baseball's first Urban Youth Academy in Compton, Calif., where he also trained this past winter. Another UYA alum, outfielder Trayvon Robinson, was called up by the Mariners on Aug. 5.
Richards is scheduled to make a rehab start this weekend at Double-A Arkansas, where he's 12-2 with a 3.06 ERA. Kevin Jepsen, a stalwart in a setup role for the Angels in 2009 and 2010, was 1-2, 7.62 for the Angels this season. Sent to Salt Lake, the power right-hander underwent knee surgery on Wednesday and is expected to be ready to go by Spring Training.