Rich Thompson and Jason Bulger, who pitched for the club in the final month of the 2007 season, are in contention for relief spots along with spring phenom Darren O'Day and Alex Serrano.
Thompson, 23, has had three consecutive superb outings since a rocky spring debut in Tucson against the White Sox -- one inning, five hits, three runs -- on March 4.
The man from Australia has put together six scoreless two-hit innings, with no walks while striking out six hitters. His spring ERA is at 3.86.
Thompson finished a victory over the Cubs on Friday with two strong innings, catching Josh Kroeger looking at a third strike to notch the save.
"That was a great hook he threw 3-2 [in the count]," pitching coach Mike Butcher said with approval.
Bulger, 29, made his fourth Cactus League appearance on Tuesday against the Brewers, walking one man and striking out a pair to finish an 11-4 win with a scoreless ninth. It's all about command with the hard-throwing Georgian who was a first-round pick (22nd overall) by Arizona in the 2001 First-Year Player Draft.
"Throw strikes, quality pitches -- in and out and get it down," Bulger said of his mission. "It's night and day from last year, when I was coming back from a shoulder injury."
Bulger, whose spring ERA is 7.20 in four appearances, fashioned a 2.84 ERA in six games for the Angels last September. Thompson had a 10.80 ERA in seven outings.
The remnants of a blister on his middle pitching finger that briefly sidelined him are visible, but Thompson has found his rhythm and form.
"The first time out I was kind of working out the kinks," Thompson said. "I can only do what I can do. It's up to them. If I keep putting up zeros, I'll definitely give myself the best chance possible."
O'Day, whose down under delivery has been an over-the-top successful this spring, worked two innings against the Brewers, with one of the two runs he allowed unearned. He is 3-0 with a 1.35 ERA.
Serrano, a 27-year-old Venezuelan, is 1-1 with a 1.86 ERA in six Cactus League games, striking out six with one walk in 9 2/3 innings.
"It's right there in front of a lot of guys," Butcher said. "We have strike throwers, guys with good stuff. We'll have to play it out, see what happens."
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.