Munson, 29, spent much of the 2006 season as Brad Ausmus' backup and will compete for the same job this year. He'll be challenged by Humberto Quintero and Hector Gimenez, the club's top two catching prospects.
Munson played in 53 games last year and hit .199 with five homers and 19 RBIs. He started 30 games behind the plate, committing one error in 275 1/3 innings at the position. In seven big-league seasons, Munson has hit .211 in 310 games with Detroit (2000-04), Tampa Bay (2005) and Houston (2006).
Randolph could challenge for a spot in the rotation, while Walker could be the left-hander in the bullpen the Astros have been seeking for much of the offseason. They would like to add another southpaw to complement veteran lefty Trever Miller.
The 32-year-old Randolph went 9-9 with a 3.67 ERA in 28 games (27 starts) with Triple-A Charlotte in 2006. He ranked third in the International League with 144 strikeouts. In 95 Major League games (six starts) with Arizona (2003-2004), Randolph is 10-6 with a 4.89 ERA.
Walker, 31, appeared in 46 games (five starts) at Triple-A Oklahoma of the Texas organization in 2006, where he was 6-5 with a 4.63 ERA. He went 0-1 with a 9.00 ERA in nine games as a reliever for the Chicago White Sox in 2005. He is 7-3 with a 4.76 ERA over parts of six big-league seasons with San Diego (2000-03), San Francisco (2004) and the White Sox (2005).
"Randolph is a starter," general manager Tim Purpura said. "He had a full complement of starts last year. We like his arm a lot. He could certainly be in
the mix for [a rotation spot]. Walker's more of a bullpen guy. He had some time in
the big leagues with the White Sox. Both of those guys are potential lefties in
the bullpen, but Randolph is more of a starter."
Ransom, who will be 31 in February, hit .247 with 21 home runs and 62 RBIs in 122 games for Triple-A Round Rock in 2006. In parts of four Major League seasons, all with San Francisco (2001-04), he hit .238 with two home runs, seven doubles and 13 RBIs.
He provides insurance at shortstop, as does Eric Bruntlett and
Mark Loretta, who signed with the Astros on Thursday.
Rodriguez, who turns 25 on Jan. 15, was 4-2 with a 2.57 ERA over 54 games (two starts) between Triple-A Durham and Double-A Montgomery in 2006. As a relief pitcher in the Venezuelan Winter League, Rodriguez went 2-0 with a 3.86 ERA over 24 games.
The Astros will host their first game at Osceola County Stadium in Kissimmee with the American League champion Tigers in an afternoon matchup on Friday, March 2 at 1:05 p.m. ET. Houston will play 30 Spring Training games, including 28 in Florida.
Individual game tickets for Astros Spring Training games in Florida go on sale Saturday, Jan. 27 at 9 a.m. CT. They
can be purchased on astros.com and also in person or by mail through the Osceola County Stadium box office (home games only), or by telephone and in person at Florida Ticketmaster outlets (home and road games).
The box office is open Monday through Friday from 10 a.m. to 4 p.m. ET and on all game days. Osceola County Stadium ticket prices are $20 for Box Seats and $17 for Reserved Seats.
Credit card purchases can be made by calling Florida Ticketmaster at (407) 839-3900. Mail orders for home games can be sent to Osceola County Stadium, 631 Heritage Park Way, Kissimmee, Fla., 34744. Checks should be made to Osceola County Stadium and include $5 postage and handling for each order.