Luis Pena was drafted in 2013, but hasn’t really made a name for himself until the last part of 2017. He’s got a plus slider and plus fastball but still needs more work on his changeup - especially if he wants to be a big league starter. That lack of a 3rd pitch is why many see him as long man out of the pen.
However, in 2017, Pena’s work load greatly increased and he threw 10 games of 6 innings+, including a complete game back in July when he struck out 12 and allowed just 1 earned run. Back in 2016 he didn’t throw a single game of more than 5 innings and most of his outings were a mix of starts and throwing out of the pen for 3-4 innings. It’s pretty clear the Angels believe in him as a starter and will continue to stretch him out. Pena has a pretty high walk rate of about 4 per 9 innings but his K/9 career rate sits around 10.
You can read a brief write-up about him here when the was mentioned as a notable in the Halos Heaven pre season prospect ratings.
Pena might have the stuff to be a big league starter some day, but I’m sure the team will continue to watch how his control and changeup develop as he climbs the ladder. He should start the year back in Mobile with the Bay Bears.