In a season where the Astros are struggling to find any kind of value on the roster, they actually have a pretty good player riding the bench. If you pull up FanGraphs Wins Above Replacement (WAR) stat for the Astros it's not a pretty sight. Michael Bourn and Hunter Pence are still in the Top 5, Clint Barmes and Carlos Lee lead the remaining rabble based on their defensive numbers. If there's ever an argument to be made against WAR and UZR Carlos Lee is it, but that's neither here nor there. After that it's newcomers Brian Bogusevic and J.D. Martinez.
It probably isn't correct to say Matt Downs is under-appreciated. In fact he's so appreciated that Brad Mills would prefer to save him for that one at bat late inning situation instead of actually giving him three or four at bats. In terms of WAR he's provided more value from the bench than Humberto Quintero, Brett Wallace and Chris Johnson...all of whom have seen regular playing time this season. Sadly he's not even the most used guy off the bench either. That distinction goes to Angel Sanchez and Jason Bourgeois. I understand Bourgeois but not Sanchez, who has actually provided the least amount of value out of the three.
So what else is there to Mr. Downs?
Well, he currently leads the team in Weighted on Base Average (wOBA) and Isolated Power (ISO). If you're into the more traditional statistics, he's first in slugging, third in on-base percentage behind Bourn and Pence (oh wait that makes him first), third in runs batted in and third in homeruns. All that in limited playing time.
It's very likely that Downs would not hit this well as a regular starter. First, his batting average on balls in play (BABiP) is above average. Second, his ISO is above his career Minor League ISO, so it might be a stretch for him to hit 20+ homeruns but it's very possible he could hit somewhere in the high teens. His walk rate is good and if his Minor League numbers are any indication his strikeout rate should improve. As for his defense, it isn't anything spectacular, but it's adequate and he should hit well enough that you're not losing anything playing him.
So why is Downs so under-appreciated? Well aside from Brad Mills' desire to save him for the late innings, Ed Wade is trying to save his job. The positions Downs is best suited for, second and third base, both presented opportunities for playing time, instead Wade decided to dip into the AA pool of talent calling up Jose Altuve and Jimmy Paredes. It's a bit ironic that in effort to save his job Wade probably could have allowed Downs to start and it would have had the same effect as the call-ups, considering Downs is another one of his good waiver claims.
As a starter Downs would allow the Astros to send down Paredes to refine his game offensively. Paredes already looks good defensively but still needs work on his offensive game as he's been extremely lucky so far. The other advantage of starting Downs is that you can find out what he can contribute as a regular with an eye towards next years trade deadline. If he proves he can be an everyday player the Astros have just added another trading chip for next year, with has the possibility of further improving the farm system.
Will the Astros give Downs an opportunity to start next year? Probably not. He's 28 and both the manager and general manager will be looking to justify their job via a player they can take credit for developing or blame for being young.