© 2013 MLB Advanced Media, L.P. All rights reserved.

7/10/2013 1:41 A.M. ET

Work with Molina's former mentor benefits Castro

ST. LOUIS -- Jason Castro has never met Yadier Molina, but the Cardinals' catcher has played a role in shaping Castro into a fellow All-Star backstop.

Castro has worked closely this season with new catching instructor Jeff Murphy, who spent the last 12 seasons with the Cardinals, including the first nine years of Molina's big league career.

"We did a lot of work in spring and he's definitely helped me a tremendous amount, kind of just refining some of the catching skills and things that worked for Yadi," Castro said. "He's been a huge asset for the catchers in this organization."

Under Murphy's tutelage, Castro is having the best season of his career. He was selected to his first All-Star Game on Saturday and punctuated it with a go-ahead three-run homer just a few hours later.

The Astros are playing in St. Louis for the first time as members of the American League, and although Houston only plays its former division foe four times this season, Castro still admires Molina from afar.

"That guys is unbelievable. To be able to catch every day like he does and still put up consistently some of the best numbers offensively in the National League, he's definitely someone that any catcher can look up to and try to learn from," Castro said. "Having played in the NL Central for a few years, definitely got to watch him on a closer basis. Now we only play him a couple times a year, but still try to take advantage of that."

Cedeno exits with contusion after fouling ball off foot

ST. LOUIS -- Astros shortstop Ronny Cedeno left Tuesday's game against the Cardinals in the fifth inning with a contusion of his left big toe. Cedeno fouled a ball off his left foot on the first pitch of his second at-bat.

"I feel OK," Cedeno said after the 9-5 loss. "I hope to get better tomorrow. We'll see."

He remained in the game to finish the at-bat, a groundout to shortstop, but was slow heading back to the dugout, and Jake Elmore replaced him when the Astros took the field for the bottom of the fifth.

"Those guys that wear those pads, I always say this: The ball hits everywhere except the pad," said manager Bo Porter. "You move the pad to the spot where you hit it, and then the ball hits where the pad use to be. So he just has a bruise and I just got him out of there because he didn't look too good running down to first base."

Cedeno said he did not know if the injury would cause him to miss any more time, but was hopeful he would be back in the lineup Wednesday.

Porter wants to rest Norris in case of All-Star call

ST. LOUIS -- Astros manager Bo Porter won't announce his rotation plans for the remainder of the first half until later this week, but he did reveal who won't start Sunday against Tampa Bay.

Porter said Bud Norris' Tuesday start against the Cardinals will likely be his last before the break. Norris is having the best year of any Astros starter, and Porter believes the right-hander is a candidate to be selected as an alternate for the American League All-Star squad. Per the new collective bargaining agreement, Sunday starters can pitch, at most, one inning in the All-Star Game, but Porter is hoping to keep Norris fresh should the opportunity arise.

"We feel like he's pitched well enough to be an All-Star," Porter said. "If it just so happened that he is selected as one of those reserves, we want him to be well-rested and be able to go in and pitch in the All-Star Game."

Porter said Norris will be ready to make the start Sunday if needed, but another off-day Thursday and the approaching break offers the Astros flexibility.

"He's been our best pitcher the whole year," Porter said. "If [AL manager] Jim Leyland feels like Bud Norris is one of those [alternates], I wouldn't want it to be hindered by the fact that he's going to pitch Sunday."

Harrell allows runs in first appearance out of 'pen

ST. LOUIS -- Just four days after his last start, Lucas Harrell found himself back on the mound, but entering in an unfamiliar situation.

Harrell, who said he was "caught off guard" by a move to the bullpen this weekend, made his first relief appearance Tuesday, replacing starter Bud Norris in the sixth inning of a 9-5 loss to the Cardinals.

Harrell pitched three innings, surrendering two earned runs on four hits, two walks -- one intentional -- and hit a batter.

"It was different," said Harrell, who entered with the Astros trailing, 7-0. "I think it's something with a little bit of time, I think I can get better at."

While manager Bo Porter said the Astros intend to "play it by ear" using Harrell out of the 'pen, the right-hander's experience as a starter allows the club flexibility to use him as a long reliever, a spot starter, or for a crucial out if the Astros are in a bind.

"If we have a starter get in trouble early, we can bring him in and he can give us length," Porter said. "If we get deep into the game and it's a situation where we need a ground ball, he's definitely a guy we know we can turn to and come in and get us out of a jam."

Harrell was 5-9 with a 5.04 ERA in 19 starts and has been inconsistent of late. He leads the American League with 55 walks, but is tied for second in baseball with 10 starts in which he allowed one earned run or less, matching Stephen Strasburg, Jeff Locke and Clayton Kershaw, and trailing Matt Harvey by only one game.

Harrell's last relief appearance was in the last game of 2011, also against the Cardinals.

"I got to pitch better or I'm not going to be here," Harrell said. "It's just the name of the game. It's life. It's one of those things where if I don't figure it out and start throwing the ball better, I won't be here anymore."

Harrell said before the game that he hadn't been told how he might be used out of the 'pen or given a reason for the move. But the 28-year-old righty still believes he can prove himself as a big league starter.

"I think what I did last year and then what I've done this year, I still feel like it shows that I can start," Harrell said. "It's just been one of those things where you have to throw strikes and you've got to be consistent. I felt like I was consistent there for a while and then the last couple starts weren't as good as I wanted them to be. But I feel like I still have a lot to offer as a starter."

Appel joins former No. 1 pick Correa in Class A

ST. LOUIS -- Mark Appel is on the rise.

The No. 1 overall pick in last month's First-Year Player Draft was promoted to Class A Quad Cities on Tuesday and will join the team Wednesday before a six-game homestand, joining last year's No. 1 overall pick, Carlos Correa.

Just four Minor League teams have had two No. 1 overall picks on the roster at the same time, but with both Appel and Correa, the River Bandits are the first Minor League club to house consecutive No. 1 overall picks.

Appel, 21, signed with Houston on June 19 out of Stanford. The right-hander made two starts with short-season Class A Tri-City of the New York-Penn League, allowing two earned runs on six hits and no walks while striking out six over five innings.

Correa is the club's second-ranked prospect, according to MLB.com, and is hitting .325 with 24 extra-base hits, 50 runs scored and 48 RBIs in 69 games with Quad Cities.

Worth noting

• Chris Carter was out of the lineup Tuesday for a third consecutive game with a minor hand injury. Carter's right hand was hit by a thrown ball Friday as he slid into second base against the Rangers. He missed Saturday's game, but pinch-hit Sunday and went through a full batting practice Tuesday at Busch Stadium.

"I shook his hand. He said, 'It's OK for me to shake your hand, but if you squeeze, it hurts,'" Porter said. "He didn't really feel too many ill effects, but I think it's good for him to go through a full batting practice today."

• Outfielder Justin Maxwell, who was placed on the seven-day disabled list with concussion-related symptoms on June 30, went 0-for-3 with a strikeout in his first rehab start Monday with Triple-A Oklahoma City. Porter said doctors will reevaluate Maxwell after a few games and if all goes well, he will return to the Astros. Porter didn't rule out Maxwell playing in this weekend's series against Tampa Bay.

"After the few days he plays, if the doctors deem him physically OK, then we're going to get him back here as soon as we can," Porter said.

Chad Thornburg is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.