The Astros were able to make a trade for Francisco Liriano at the trade deadline. However, the transition from starter to reliever was not smooth. While he eventually settled down, he had one little unfortunate appearance in the ALDS and A.J. Hinch was scared to use him.
The Astros have considered whether to re-sign Liriano according to Jake Kaplan, but he may be looking for a chance to start again. Many fans would not like a Liriano reunion. There are only so many options on the free agent market, so they were looking for other options.