JUPITER, Fla. -- If Thursday was any indication of the positioning Joe Kelly and Shelby Miller have found within the competition for the final rotation spot, the margin of separation between the two is minimal.
Miller followed Kelly on the mound in the Cardinals' 5-4 win over the Braves. And though Kelly posted the more impressive numbers on this day, both right-handers have made compelling arguments for their inclusion in the starting five.
Manager Mike Matheny said after the game that no decision has been made regarding the season opening assignment for either pitcher. He added, too, that the club could allow Kelly and Miller to pitch again this spring before a fifth starter is officially selected.
"Today wasn't a drop-dead, have-to-make-a-decision day," Matheny said. "Just take in more information and another opportunity go out there. I thought they both did the most with it."
Matheny did, though, provide some insight into how different factors will be weighed in the decision. He suggested that the impression each pitcher makes this spring will be more influential than the job each did in the Majors last season.
"You have a hard time really ignoring what Joe did," Matheny said, alluding to the 16 starts Kelly made for St. Louis in 2012. "He came in and gave us a great opportunity to win every time he started. He gave us quality starts. But we also know that Shelby took advantage of the opportunities he had. We took that into consideration, but right now we just look and see where they are right now because that's what we need. We need the guy who is ready to go for us."
Kelly covered the first four innings of Thursday's game, throwing 32 of his 50 pitches for strikes. He didn't walk a batter, which was notable since he had walked five in his first four innings this spring.
Kelly took the mound deliberately working on his tempo, which had been slower than desired in his first two appearances. He also maintained a more direct stride toward home and threw a heavy dose of four-seam fastballs. Both were facets of his game that he wanted to target.
Honing in on what he needs to do to be best prepared for the season, Kelly said, outweighed any temptation to pitch simply to get results that would impress in the two-man competition.
"I was just working on trying to get better," Kelly said. "Competition is good. Until something is said and something is written down, I just go out there and pitch when they want me to pitch."
Miller's intention was much the same. He threw more changeups on Thursday than he might normally because it's a pitch he wants to incorporate more often this season. A few were among those the Braves hit en route to scoring three times on six hits.
Miller struck out four to increase his spring total to eight in 7 2/3 innings.
"I feel like I've been throwing well," Miller said. "I definitely have been throwing better than what the numbers look like. I felt good and I feel like my fastball is a lot better than it was last year. But at the same time, Joe has thrown just as good. … I feel like there's always room to prove that I was more ready. But at the end of the day, Mike is going to do what is best for the team."
The interesting wrinkle in this battle, too, is that it is between best friends. Miller and Kelly are sharing a condo this spring and will serve as the best man in the other's weddings next fall. Those weddings will take place one week apart.
Both say that friendship has not been compromised through competition.
"We talked after today," Kelly said. "I said, 'Your changeup looks good, fastball was good.' It is what it is. We're not trying to hide from each other. We live together, too. We converse with everything we do all day."
"If he gets the fifth spot, I'm not going to talk to him anymore. No, I'm kidding," joked Miller. "It's not going to change anything. I'll be happy for him. But I'm sure if I got it, he'd be just as happy for me."
Once the Cardinals select a fifth starter, they'll have a second decision to make, too. That will be in determining where to send the pitcher who doesn't win the job.
One of the options is to transition him into a relief role, just as Trevor Rosenthal did after being bounced from the rotation competition. Or he could start in Triple-A, giving the Cardinals an insurance option for when there is a later need for a starter at the Major League level.
If the odd man out is Kelly, a bullpen role would seem a natural fit for the right-hander. He was key in the Cardinals' bullpen late in last season and throughout the postseason in 2012. He also pitched as a closer in college.
If Miller is squeezed out of the rotation, the bullpen likely isn't in his immediate future. He doesn't have much experience pitching in relief and it isn't seen as a role that he'll assume later in his career. As a result, there would seem to be value in keeping Miller stretched out.
Matheny, though, wouldn't hint which direction, if any, the club was currently leaning.
"We still have a long way to go here and things seem to happen to define that," Matheny said. "We just have to have our eyes open and see what is going to be the best fit overall. We just have to look at the bigger picture when that time comes."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.