"We do feel like any time we take someone off the roster we risk losing a player we want to keep, so any addition would have to be considered in that light," Luhnow said. "In terms of our goals for this offseason, we wanted to improve our lineup offensively, we wanted to add some depth to the bullpen and add some depth to the starting rotation, and I think we've done all of that to a certain extent."
Pena, signed Dec. 17, will be the Astros' first full-time DH, though he will certainly get plenty of playing time at first base. He's averaged 32 homers, 91 RBIs and 94 walks the past six seasons, but his batting average has fallen below his .234 career mark the past four years.
Veras was signed by the Astros on Dec. 21 after going 5-4 with a 3.63 ERA in 72 relief appearances for the Brewers last year. He's likely going to be the Astros' closer entering the season unless one of their young arms -- Josh Fields or Rhiner Cruz -- blows away the competition in Spring Training.
Houston added Fields with the top pick in last month's Rule 5 Draft and 6-foot-7 slugging first baseman Nate Freiman with the top pick in the second round of the Rule 5 Draft, and both of them could play key roles as well.
"I think we've accomplished most of our goals," Luhnow said. "Entering Spring Training, our approach is going to be to monitor the market and be opportunistic, and if we feel like there's a free agent who's still out there that can improve our club that's a decent fit in terms of we have playing time available for them, they don't come at a cost of risking losing someone off the roster that we don't want to lose, then we're going to continue to look at those opportunities.
"I'm sure there will be some activity in that regard, and we'll continue to talk to clubs to see if there's a match somehow. ... We feel like we've got enough quality players to come to camp and field a competitive team at this point."
The Astros are set at catcher with the return of starter Jason Castro and backup Carlos Corporan, and Luhnow is content with an infield alignment that includes Matt Dominguez at third base, Jed Lowrie at shortstop, All-Star Jose Altuve at second base and mix of Brett Wallace and Pena at first.
When asked if Freiman would have a hard time getting at-bats with Wallace and Pena playing the same position, Luhnow said Freiman's right-handed stick sets him apart from the two veteran lefty swingers. Freiman must stay on the 25-man roster all season or be offered back to the Padres.
"It's going to come down to the final few days of Spring Training to see how the roster shakes out, but there are several scenarios we've talked through that include having him on the club," Luhnow said. "It's a big jump from the Texas League to the big leagues, but if he hits the way we hope he will, he'll work his way on the team."
If there is one area where the Astros may still add another piece, it's the outfield. There is no shortage of bodies with J.D. Martinez, Justin Maxwell, Fernando Martinez, Jimmy Paredes and Brandon Barnes all in the fold, and Houston signed Trevor Crowe to a Minor League deal as well.
"We have plenty of options in the outfield, but that's probably one area where if there were a free agent out there that could substantially help us offensively, that's the area we might be able to plug him into the outfield," Luhnow said. "We'll still keep an eye out for that."
Luhnow likes the depth in the starting rotation, where six pitchers are going to come to camp battling for the final three spots in the rotation behind Bud Norris, Lucas Harrell and Jordan Lyles. And Luhnow gives veteran Philip Humber a nod for the fourth spot.
That would leave lefty Dallas Keuchel, newcomers Alex White and John Ely, veteran Edgar Gonzalez (a non-roster invitee) and top prospect Jarred Cosart in contention for the final spot in the rotation when camp begins Feb. 11.