Even though Haren is 6-7 on the year and has a 7.94 ERA over his past four starts, Scioscia knows he's dealing with the same talented righty who threw a four-hit shutout in Seattle on May 24.
"We have every confidence that Dan's going to be the guy we've seen, and at times he's shown it this year," Scioscia said. "It's not too far of a stretch to see him getting back and being the productive pitcher that he can be."
Haren's next chance to get back on track comes Tuesday in Cleveland.
The 31-year-old has struggled with tightness in his back, and his pitches have been slightly up and a little flat.
Scioscia said Haren understands his issues and has made a few adjustments, giving hope that he can look more like the pitcher who was 16-10 with a 3.17 ERA in 2011, and less like the one who is 6-7 with a 4.53 ERA in 2012.
"There's no doubt he has the ability to get on a roll and give us a big boost in our rotation," Scioscia said. "It's in him, no doubt."
Zach McAllister, who will take the hill for Cleveland, appears to be settling in as the Indians' fifth starter after some time bouncing between the Majors and Minors.
The righty is 2-1 with a 3.29 ERA and a 1.07 WHIP in his last seven Major League starts, dating back to last season. He has not given up more than four earned runs in any of those games.
"He has given us an opportunity in all those outings that he's had," Indians manager Manny Acta said. "He's a guy that continues to make improvements, not only command of his fastball, but also his secondary pitches."
McAllister naturally appreciates the vote of confidence, but understands how fickle time in the Majors can be for a 24-year-old pitcher.
"It is helpful," McAllister said. "But at the same time, I also know that if I don't do my job, I can get sent down. I definitely have that type of mindset of knowing that I have to perform. If I don't, it's not acceptable."
Angels: Trout day to day with pinkie injury
All-Star rookie center fielder Mike Trout was scratched from the Angels' lineup on Monday because of a sore right pinkie finger, but entered the game as a pinch-runner in the eighth inning.
The 20-year-old, who on Monday became the first player since Brennan Boesch in 2010 to win American League Rookie of the Month in consecutive months, had made 49 straight starts.
X-rays on the finger were negative, and Trout is considered day to day.
Erick Aybar has hits in 17 of his last 19 games, and is hitting .400 in that stretch after going 2-for-4 with a sacrifice fly on Monday.
Indians: Hafner nearing return
Acta said the Indians expect to activate designated hitter Travis Hafner prior to the All-Star break.
Hafner, who is on the 15-day disabled list with a right knee injury, continued his rehab stint with Triple-A Columbus on Monday, going 0-for-4 with a hit by pitch.
After missing the previous four games with soreness in his back and side, catcher Carlos Santana started on Monday.
Santana caught Aybar trying to steal second on the third pitch of the game, and grounded a single up the middle in his first at-bat.
After hitting a single in the seventh inning on Monday, Michael Brantley has recorded hits in 34 of his last 37 starts.
The Indians' active roster has a career .198 batting average and .273 slugging percentage against Haren.