Pipeline Inbox: Who will develop into a franchise arm?

Spring Training games have begun, and it's a great time of year for fans because they can follow just about every Grapefruit and Cactus League game and see prospects aplenty getting some big league action.

I'm currently in Florida, going from camp to camp and talking to and about those prospects for upcoming Spring Training reports -- MLBPipeline.com style. Stay tuned for those, but in the meantime, here's this week's Inbox to whet your appetite.

If you had to start a franchise, who would you take: Lucas Giolito, Kohl Stewart, Julio Urias, Carlos Rodon or Eddie Butler?
-- Jim S., Booneville, N.Y.

That kind of question is always an interesting exercise. If I had my druthers, I'd try to find an impact hitter, one who plays every day, but I guess I have to work with the cards I've been dealt.

As much as I really like Dodgers lefty Urias, I think his ceiling is more limited than the others included in the question, despite being a southpaw. If you wanted to go in order of Top 100 ranking, it would go: Stewart (40), Butler (41), Giolito (44), Urias (64). Of course, that doesn't take Rodon into account, because he has yet to play professionally.

I'd be tempted to go with Rodon, a North Carolina State lefty and currently everyone's front-runner to go No. 1 overall in this June's Draft. But we're talking about a guy who hasn't thrown a pro pitch yet, so there's risk involved. I like all of the other right-handers, but I think if I was going to take one of them, I'd go with Giolito. He's throwing extremely well after having Tommy John surgery in 2012. If that continues, Giolito has a chance to be a legitimate No. 1, a true ace. And who doesn't want to build around one of those?

What A's prospect(s) not named Russell could you see jumping into the Top 100 by the end of 2014 or start of '15?
-- Casey H., Oakland

In my early travels through Spring Training, I had a conversation with a team executive about which team had the biggest drop-off from their top prospect to the No. 2 guy in that team's system. His answer was the Oakland A's.

Shortstop Addison Russell is currently ranked No. 12. There isn't another A's prospect on the Top 100. By those standards, that is the biggest drop-off. While there are other teams with just one representative in the Top 100, none are ranked as highly as Russell.

The question is not easy to answer, because there's no obvious choice. But the best possibility, to me, is the high school hitter the A's took in the first round the year after they took Russell in 2012. That would be Billy McKinney.

Taken No. 24 overall, McKinney hit .326/.387/.437 in 55 games during his pro debut, earning a promotion from the Rookie-level Arizona League up to the more advanced short-season New York-Penn League. The guy can hit, and if he swings the bat well in 2014, especially if he goes to full-season ball, I could see him getting some consideration by next year. Oakland's new Top 20 comes out on March 31. I'm not doing that list (Jim Callis is all over it), but I think it's quite reasonable to think McKinney will move up from the No. 7 spot he filled at the end of the 2013 season.

Does the weight loss of Dan Vogelbach change his outlook for you? What do you think of his effort in this regard?
-- Dan H., Guttenberg, Iowa

We had Vogelbach as the No. 4 first-base prospect this year, and even though it's not a great group of first basemen, it still shows that we thought fairly highly of his ability with the bat.

The 2011 second-rounder has 60 grades for both hitting and power. Very few doubted Vogelbach's ability to hit for average and home runs as he moves up the Cubs' ladder. The problem, of course, was his well-below-average defense and speed, as well as concerns about his conditioning. The fact that Vogelbach worked hard and took off that much weight is an encouraging sign that he's serious about getting, and hopefully staying, in shape.

Vogelbach was a designated hitter 39 times and played first 92 times last season. Many felt he was destined to be a DH-only type. Vogelbach may never be a defensive asset, but if he can increase his agility, it can only help. It would also increase the chance of him staying with the National League Cubs.

Can a future rotation of Kohl Stewart, Alex Meyer, Jose Berrios and Lewis Thorpe win a championship for the Twins?
-- Thomas B., Sioux Falls, S.D.

Ignoring the obvious response of needing some offense to go along with that quartet (not to mention a fifth starter and a bullpen), let's look at the true meaning of the question: Is this the core of a championship-caliber rotation?

It certainly could be. Stewart, Meyer and Berrios are all in the Top 100. When the Twins' Top 20 comes out on March 14, Thorpe won't be too far behind that trio. But the key word is potential. Meyer is the only one in this group at the upper levels of the system, with Stewart and Thorpe yet to experience full-season ball and Berrios just having one campaign under his belt.

In other words, it's a bit too early to tell. The potential is certainly there. Meyer's future overall grade is a 65, Stewart is a 60 and Berrios earned a 55. I don't want to spill the beans too much on the new Top 20, but I can tell you that Thorpe gets an overall 50, though there's room for him to improve that, given how far away from the big leagues he is. That gives Minnesota the potential to have four above-average starting pitchers if it all comes together. And that, typically, means good things for a team's success.