When discussing off-season acquisitions 3 areas have consistently come up on this site. The bullpen (obviously). A corner outfielder (I don't think this is as pressing, I wouldn't mind seeing how Grossman, Hoes and farm options develop over the next season but I wouldn't argue against a signing). And a starting pitcher. It is in this area I suggest Ricky Nolasco, here's what I like about the signing.
First it shouldn't break the bank, signing a big dollar free agent still seems a season or two away for me. Nolasco will cost some coin but nothing eye popping. I think 4yrs/50 million could get it done. I've seen fangraphs predictions anywhere from 3yrs/30 million to 4yrs/56 million.
He's been good the last three years posting WARs of 3.1, 2.5, 3.0 with FIPs of 3.54, 3.87, 3.34 (his ERA has been inflated by a high BABIP) but what I really like is his IP 206, 191, 199. It points to consistency and durability. Bullpens and managers love a pitcher like that.
A 4 year contract takes him to 35, old but not to the point where him still be effective seems highly unlikely. He'll strengthen the rotation immediately next year and in a couple of seasons when some combination of Cosart, Appel, Folty, Wojo, McCullers, Rodon? are emerging Nolasco could be a solid 4-5 starter on a playoff contender.
It a signing that shows the Astros are starting to look at winning on the ML level but won't handcuff them for the next 8-10 years.