Guillon was added by the Reds when he was 18-years-old out of Venezuela in 2010. After seeing success early in the lower levels, the organization with slow on promoting the left-handed starter, and he was still in Low-A in 2014. He was promoted to High-A Bakersfield in 2014, but really struggled with contact and was DFA’d when the Reds added Burke Badenhop to the bullpen in 2015. Guillon has seen an occasional start, but is working mostly out of the Daytona bullpen in 2016. His fastball sits high-80s to low-90s with a change and curve both in the low-80s.