When Matt Klentak took over the Phillies, Ruben Amaro had already gutted the team of all of the veterans of value. This didn't stop from Klentak from putting his mark on the team by shipping out his closer for a bunch of unproven players. The most prominent of those pieces was right handed starter Vincent Velasquez.
To put Velasquez's season in context you need to start with a number, and that number is 12. That being the number of starts that Velasquez had at levels AA or higher entering the year. Now there are many reasons why a 23 year old would not have upper minors experience, some is a history of injury, some is the Astros' need for relief pitching late in 2015 over starters.