McGuire will start Sunday's game in Baltimore, Jeff Fletcher of The Orange County Register reports.
John Lamb was placed on the disabled list with shoulder and elbow inflammation, so McGuire, who was recalled from Triple-A last week, will get the spot start. He logged four innings, giving up three earned runs and striking out one, in his last appearance on Tuesday after Lamb left with the injury. McGuire only threw 55 pitches in that appearance, but he was up to 92 pitches in a Triple-A start June 7, so it's possible he goes deep enough to qualify for the win. The 29-year-old journeyman has a 4.33 ERA and 5.58 xFIP in 27 MLB innings, so expectations should be tempered. The Angels currently have seven MLB starting pitchers on the disabled list, so it's possible McGuire can stick in the rotation if he turns in even a middling performance.