SCOTTSDALE, Ariz. -- It's now likely that reliever Bobby Cassevah (slight labrum tear) will begin the season on the disabled list, and the Angels aren't quite sure when Michael Kohn (forearm strain) will return.

Suddenly, a couple of spots may have opened up in the bullpen.

"With Kohn and Cassevah, two guys who were in the mix to win a spot, it takes some things out," Angels manager Mike Scioscia said. "But I don't think there's going to be a shortage of arms we're going to trust to come in and get outs and hold leads for us."

Closer Jordan Walden, veteran right-hander LaTroy Hawkins and the two lefties, Scott Downs and Hisanori Takahashi, are locks for four of the seven spots in Scioscia's bullpen.

Then there's Jason Isringhausen, the 39-year-old former closer who came in on a Minor League contract and will appear in games on Wednesday and Thursday. Isringhausen will go into them with something to prove, after giving up four runs in 3 2/3 innings this spring -- including three while only recording two outs in Sunday's ninth inning.

And there's Kevin Jepsen, who made 122 appearances for the Angels from 2009-10, underwent knee surgery last season and now seems to have regained the life on his fastball.

Jepsen has given up four runs on six hits and four walks in eight one-inning appearances this spring, but Scioscia believes that line isn't indicative of where Jepsen is, saying: "His stuff is coming out hot, he's doing some things that are going to make him more pitch-efficient and he's throwing the ball very well."

The other relievers still in camp are Trevor Bell (3.72 ERA in 9 2/3 innings), Francisco Rodriguez (3.12 ERA in 8 2/3 innings) and Rich Thompson (2.25 ERA in eight innings). Of that group, only Thompson is out of options.

Kohn, who has hurled five scoreless one-inning appearances this spring, is expected to stay away from throwing for the rest of the week. Cassevah was expected to throw a bullpen session on Tuesday, but he has yet to appear in a Cactus League game and probably won't start the season with the club.

"He's obviously behind on where we wanted him, but we'll see how he progresses," Scioscia said. "Right now, it's doubtful he's going to be ready at the start of the season, but hopefully he'll be ready shortly after that."

Mills encouraged by his spring with new team

SCOTTSDALE, Ariz. -- Brad Mills may not have a real shot at being the fifth starter to open the season, and to Angels fans, he may always be known as The Man Acquired For Jeff Mathis. But he has managed to put together a really nice spring -- regardless of velocity.

"Deception, changing speeds, kind of a herky-jerky motion and throwing strikes" is what the Angels' new soft-tossing left-hander credits to his success. "I don't worry about velocity; I've never asked about the gun. I feel like I have enough on my fastball. It plays. I don't feel they're all over my heater. They're fouling it on the late side all the time, so as long as that's going on, I know I have enough on it."

Mills, 27, was originally drafted by the Blue Jays in 2006, but went back to school to get his civil engineering degree at the University of Arizona, then was drafted by them again in the fourth round the following June.

With a high release point, a mid-80s fastball, a slow 12-to-6 curveball and a 70 mph changeup, Mills found some success in the Minor Leagues, posting a 4.32 ERA while making 58 starts in Triple-A's incredibly hitter-friendly Pacific Coast League the last three years. During that span, he also compiled 48 1/3 innings in the big leagues, putting up an 8.57 ERA along with it.

Not great. But when you're dealing Mathis -- a weak-hitting catcher who was expected to be non-tendered because the Chris Iannetta acquisition left him without a role -- you can't expect much anyway.

Upon acquiring Mills from the Blue Jays on Dec. 3, the Angels at least got someone who's serviceable. And this spring, Mills has been even more than that. He came into Tuesday's 5-3 win over the Giants with 8 2/3 scoreless Cactus League innings, then gave up two runs in six innings.

"His ability to change speeds makes his fastball play up a little bit, and I think you saw that today," manager Mike Scioscia said.

Mills will likely start his 2012 season in Triple-A Salt Lake -- it'll be up to Garrett Richards and Jerome Williams for the rotation's last spot -- and that wouldn't necessarily disappoint him, regardless of how good his March has gone.

"As long as I keep getting my innings, keep getting better, that's OK," Mills said.

Considering how a sector of Angels enthusiasts felt about the man he was traded for, Mills could never throw a big league inning for the Angels and fans would still love him.

But the crafty left-hander only sees good things from Mathis.

"I know he was a former first-rounder and other pitchers say they love throwing to him," Mills said. "I love catchers like that, too. If I was the manager of the team, I wouldn't care what my catcher hit. If he hit .100 but caught a heck of a game, that works for me."

Trumbo makes good on first look at slow roller

SCOTTSDALE, Ariz. -- The toughest play for the Angels' Mark Trumbo in his quest to be an adequate Major League third baseman is the slow roller, which tends to be pretty difficult for a man listed at 6-foot-4 and 220 pounds.

At last, in Tuesday's 5-3 win over the Giants at Scottsdale Stadium, Trumbo finally got his chance to convert one in a game, charging a softly-hit grounder by Emmanuel Burriss and swiftly throwing to first base for the easy out in the fifth.

"It was good," Trumbo said. "I feel confident. We've done so many reps now that I feel like I have the basic footwork down. I feel good coming in on it. No hesitation or anything. I know what I need to do to give myself a chance on that play now."

Trumbo made that throw overhand, mainly because he fielded it with his glove and had time. The 26-year-old said he feels comfortable making the throw below his shoulder on barehand plays, too, though he hasn't been able to put that on display just yet.

Trumbo is tied with Alberto Callaspo with a team-high three errors at third base, but has turned in a few nice plays -- including snagging a hard-hit line drive while playing even with the bag on Tuesday -- and is more ahead in his progress at the hot corner than many envisioned.

Worth noting

• While pitching in a Triple-A game at Salt River Fields in Scottsdale on Tuesday, Jered Weaver hurled six scoreless innings, giving up three hits, walking two and striking out seven. Kendrys Morales and Mike Trout were both designated hitters and each had two hits.

• Alexi Amarista continued to make his case for the final bench spot, lacing a three-run triple to right field to break a 2-2 tie in the ninth inning on Tuesday. The versatile Amarista, who plays the middle infield and all three outfield spots, is hitting .349 this spring.

"He's had an incredible spring," Angels manager Mike Scioscia said. "There are definitely a lot of things that he can do that's valuable to our club, and he just keeps bringing it every day. It's been fun to watch."

• Bobby Abreu's batting average dipped below the .100 mark after going 0-for-2 with a walk, making him 4-for-42 (.095) in Cactus League play. When asked if he needs to start seeing some results from Abreu, Scioscia said: "I don't think anything's changed from the last couple of days we talked about Bobby. I think he is getting a little more timing -- he hit the ball well to center, got a walk. There's some things that's showing him seeing the ball better. We need production from a lot of guys."