Summoned from Triple-A Salt Lake to get some outs and relieve some stress on the bullpen, Arredondo, 24, has shown the right stuff to manager Mike Scioscia and closer Francisco Rodriguez -- after a less than auspicious beginning.
The third pitch and first strike of his Major League career was launched for a home run on Wednesday night by Nick Swisher of the White Sox.
"That wasn't too good," Arredondo said, grinning.
It quickly got better. He retired the side, striking out one hitter. Two nights later, asked to get one out, he struck out Orlando Cabrera, the Angels' former shortstop, with a split-fingered fastball.
"That felt much better," Arredondo said, having expressed his pleasure with a gesture calling to mind K-Rod.
The closer has been helpful to the young man from San Pedro de Macoris, Dominican Republic, who began his professional career as a shortstop and reminds Rodriguez of himself in some ways.
Even Swisher's jolt brought back memories for K-Rod, who made his Major League debut in September 2002 and was a postseason legend a month later.
"I want to help him be confident," K-Rod said. "It's pretty much the same situation as when they brought me up. [Eric] Chavez was my first hitter, in Oakland, and he got a base hit.
"After that, I had a strikeout [run] of nine in a row. It ended when I walked Travis Hafner intentionally in Texas."
This type of reinforcement and wisdom, from K-Rod to the kid, can be immeasurably beneficial.
"He's got a great arm," K-Rod said of Arredondo, who was superb this spring and off to a great start in Salt Lake. "He has the ability to be a good setup man or closer. He's got a really good two-seam fastball, a slider and split. He can get people out with what he has."
Arredondo's two-seamer reaches 94 mph on the gun, similar in impact to Scot Shields' killer sinker.
"That kind of stuff plays well in anybody's bullpen," Scioscia said. "He still has a learning curve, but he's shown he can get people out."
When Dustin Moseley returns to claim his middle-relief role, Arredondo is expected to be back in Salt Lake, closing. Moseley will throw 75 pitches in a rehab assignment for Salt Lake in Sacramento on Sunday.
"When a guy pitches well, he makes a role for himself," Scioscia said. "If Arredondo keeps pitching well, not only is he making a spot for himself, but he gets an expanded role."
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.