Looking to avoid losing a fifth consecutive start, Ventura takes the mound opposite Michael Wacha as the Royals wrap up a four-game, home-and-home series against the visiting St. Louis Cardinals on Thursday night.One of the hardest throwers in the game, Ventura (2-5, 3.45 ERA) surrendered a career-high five runs before exiting with two outs in the third inning of a 9-2 loss to Houston on May 26. While Royals fans feared the worst, the 23-year-old right-hander is set to return after missing one start."He was getting under pitches and his velocity was starting to drop a little bit. That's when we decided to go out and check it," manager Ned Yost told MLB's official website. "The trainers were right on it, and they came two minutes later and said it's the outside of the elbow, and that's where my concern dropped way off."Ventura, who went 2-1 with a 2.00 ERA through his first six starts, has since dropped his last four while compiling a 5.91 ERA. It's unclear if his pitch count will be limited Thursday."Right now, I don't feel any pain and I'm very grateful to God and the trainers for working with me so I can continue to get better," said Ventura, who has received a combined four runs of support during his losing streak. "It could've been worse. I'm very thankful to God that everything is working out."Ventura could have difficulty keeping pace with Wacha (4-3, 2.45), who is 2-0 with a 1.73 ERA in his last four starts. The right-hander struck out seven over six innings and combined with three relievers on three-hitter in Saturday's 2-0 win over San Francisco."This guy's going to be tough as nails, if he's not already," manager Mike Matheny said of last fall's NLCS MVP. "You can't put a young pitcher through much more than what he's been put through."Wacha has gone 0-3 despite a 2.51 ERA over five road starts while receiving a combined five runs of support. He hasn't faced the Royals (28-31) since allowing two hits over seven innings of one-run ball in a 4-2 loss last May 30 in his major league debut.The Cardinals (31-29) had dropped six of seven -- including back-to-back home losses to Kansas City -- before winning 5-2 in 11 innings at Kauffman Stadium on Wednesday. St. Louis blew a two-run lead in the ninth before storming back for its eighth straight victory in Kansas City."It was just one of those gut-check games," first baseman Allen Craig said. "We're not going to stop competing."Matt Carpenter came up huge with a career-high five hits, including the go-ahead double in extras."Sometimes it takes an emotional victory like this to kind of jump-start a team," said Carpenter, who also reached on a walk. "Maybe this one will be the one for us."Carpenter has hit safely in 16 of 17, going 30 for 70 (.429) with 10 extra-base hits and 11 runs. He is batting .439 with seven extra-base hits and 10 runs in 10 games against the Royals.Kansas City has hit .196 and been outscored 26-7 during a four-game home losing streak. Catcher Salvador Perez is 2 for his last 22 at home.