Hearn was added to the Rangers' 40-man roster Tuesday.
Hearn was traded from the Pirates to the Rangers at the July trade deadline for Keone Kela and is one of the organization's top pitching prospects, so it's unsurprising to see him protected from the Rule 5 draft. The 24-year-old lefty spent the 2018 season at the Double-A level and had a 3.12 ERA, 1.09 WHIP and .198 opponent batting average with Altoona prior to the trade. He subsequently struggled with Frisco, posting a 5.04 ERA, 1.52 WHIP and .284 BAA over 25 innings.