KISSIMMEE, Fla. -- It was nothing short of trial by fire. With their bullpen undergoing a massive overhaul in the second half of the season, the Astros called up fresh arms from the Minor Leagues and were forced to put them in big situations under the bright lights of the big leagues.
At one point last August, the Astros featured five rookies in a seven-man bullpen that took its lumps following the trade of veteran closer Jose Veras. Suddenly, it was up to young arms like Josh Fields, Chia-Jen Lo, Josh Zeid and Kevin Chapman -- all of whom made their Major League debuts last year -- to hold leads and close out games.
There were some promising signs and some low points, but the experience the Astros' pup relievers gained in 2013 sets them up to contribute nicely this season.
"It was really fun for us to be able to do that," Chapman said. "It was a blessing for us to get the experience and be in some high-pressure situations at the end of the game and be able to come out and good or bad, you can learn from it either way."
All four of those relievers know nothing is a given this spring, except for some long bus rides and a chance to compete. They're battling for four spots in the bullpen, with veterans Chad Qualls and Matt Albers guaranteed roles and Jesse Crain taking a spot when he's healthy.
There's competition, too, from hard-throwing Anthony Bass and Rhiner Cruz and newcomers Raul Valdes, Peter Moylan and Darin Downs.
"The fact that we have veterans that can teach us starting now and throughout the season, I'm personally extremely excited," Zeid said. "If we mess up, someone's going to get on us. If we don't do the right thing at the right time, someone's going to make sure we know what we did wrong or how to correct ourselves in game, out of game, on the field, off the field."
Getting a chance to pitch for the Astros, a team that was rebuilding, was the perfect situation for Fields.
"We had opportunities here we wouldn't have had on other teams and another organizations," Fields said. "It was a great learning experience for me and a lot of guys. Just the opportunities we had here and the way the team was so young, we had opportunities to fail and chances to get back out there and do it again. That was what was nice to know -- they were going to give us shots."
The signings of Qualls, Albers, Crain and Moylan should lead to an improved bullpen. Last year, the Astros finished last in the Majors with a 4.90 ERA by the relief corps and tied for the lead with 29 blown saves with the D-backs. So bolstering the bullpen with vets was vital.
"I absolutely love the fact that we have veterans on our team," Zeid said. "Even though five or six relievers got called up last year, we're all still rookies and none of us really know how to play a game at the Major League level. We may have [little] experience, but there's still a lot of things we can learn.
"Chad and Matt have been great and we can't wait to see Jesse throw, but for now Chad and Matt have been great coaches and great mentors, and I can't wait to see how that works out."
Zeid, a right-hander, made his Major League debut on July 30 at Baltimore and wound up making 25 relief appearances, posting a 3.90 ERA in 27 2/3 innings. He stranded 15 of 17 inherited runners and allowed a .178 average against left-handed hitters.
"There's a little bit of an element of surprise," Zeid said. "When everybody is a rookie or doesn't have a lot of experience, a lot of the hitters may take us for granted. Who really knows? It's one of those things where competition really does come into play. If Chappy goes out there and throws up a zero, of if he leaves a runner on, we all want to come in and shut the door because we're all new to this."
Chapman, a left-hander, was called up Aug. 9 and set a franchise record by not allowing an earned run in his first 13 Major League appearances. He stranded 16 of 19 inherited runners and held opponents to a .183 batting average.
"Baseball is the type of thing, the more experience you have the better," Chapman said. "It's a game where you're constantly learning, and having guys like that in the pen is definitely going to help all of us and anybody who comes up throughout the year."
Lo, a right-hander, was called up along with Zeid, though he came straight from Double-A. He made 19 appearances and split the save opportunities with Fields, picking up three saves in five chances. He held lefties to a .128 batting average.
Fields, a right-hander, was on the Astros' 25-man roster the entire season after being taken in the Rule 5 Draft in December 2012. He appeared in 41 games and converted five of six save chances and struck out 40 batters in 38 innings.
The bullpen began to jell in September once it developed camaraderie and had some experience. After posting a 5.71 ERA and converting only six of 16 saves in August, the relievers had a 3.52 ERA and saved four of eight chances in September.
"We definitely had a good time, just getting to know each other," Chapman said. "Once that happened, we were down there and we had some good chemistry going. I feel like that's why towards the end of the year we started doing better and clicking, is we were on each other's sides, we had each other's backs. If one day I came and didn't do my job, somebody would come and pick me up, and vice versa."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter.