Pipeline Inbox: Which hurlers have most potential?

I hope all of you are enjoying the holiday season. While everyone has been celebrating, some of you have been stuffing the MLB Pipeline Inbox with questions. Let's answer a few of them now ...

In my opinion, the top five pitchers to make their Major League debuts last season, in terms of career potential, were Jose Fernandez, Gerrit Cole, Michael Wacha, Zack Wheeler and Taijuan Walker. I'm not including Hyun-Jin Ryu, because I believe that international players fall under a different category. Who do you think the next-five-best debut pitchers were?
-- Joe M., Toronto

Those would be my same top five as well, and there are plenty of other talented pitchers who made their big league debuts in 2013. The next two would be Kevin Gausman and Sonny Gray, followed by Carlos Martinez, Jarred Cosart and Yordano Ventura.

Limiting me to a second top five leaves out several more intriguing arms: Allen Webster, Danny Salazar, Kyle Gibson, Brandon Maurer, Erik Johnson, Alex Wood, Jimmy Nelson, Brandon Workman ... It was definitely a strong year for pitching debuts in 2013.

Can you compare Brady Aiken to Trey Ball (Red Sox) and Max Fried (Padres)?
-- Byron H., Taipei, Taiwan

Aiken, who ranks No. 9 overall on our initial Top 50 Prospects list for the 2014 First-Year Player Draft, is the best high school left-hander available. The same was true of Ball in '13 and Fried in '12, when they went seventh overall in their Drafts, so this makes for a good comparison.

Aiken has a more physically mature frame at 6-foot-3 and 210 pounds than the more projectable Ball (6-foot-6, 180 pounds) and Fried (6-foot-4, 189 pounds). Despite that, Aiken has less arm strength at the same stage, usually working around 90 mph, while Ball worked at 91-94 throughout his senior season and Fried maxed out at 95. Aiken's fastball still projects as an above-average pitch, because he commands it well and it features a lot of run and sink.

Aiken is probably more similar to Fried. They were both more a little more polished than Ball, had a little more advanced curveball and had a little bit better changeup. I'd rank them in this order: Fried, Ball, Aiken. It's close, though, and Ball may have the highest ceiling and Aiken the highest floor.

What's the general consensus on catcher Andrew Susac? It seems like he goes unnoticed outside Giants circles.
-- Kyle G., Billings, Mont.

Relative to his talent, Susac is one of the more underhyped catching prospects in baseball. A 2011 second-round pick who signed for $1.1 million out of Oregon State, Susac has the tools to become a big league regular. He stands out most for his offensive potential, as he combines above-average raw power with patience at the plate.

Susac needs to clean up his receiving, but he has a strong arm and should be at least an average defender. His biggest needs are to make more consistent contact at the plate and to do a better job of staying healthy. A broken hamate bone marred his Draft year, and he missed part of 2013 with shoulder issues.

What do you think of the White Sox trades to get young talent in the door?
-- Nathan O., Lansing, Mich.

White Sox general manager Rick Hahn is doing exactly what he should be doing. His club is coming off its worst season since 1970, and it had little in the way of young position-player talent in the Majors or Minors. Since the end of July, Hahn has swung three deals to acquire players Chicago hopes to build its lineup around for the next few years.

Jettisoning Jake Peavy in a three-team deal netted Avisail Garcia, who could be a .275 hitter with 20 homers in right field, as well as three lower-level prospects while saving roughly $20 million in salary. Another three-team trade turned surplus starter Hector Santiago and middling prospect Brandon Jacobs into Adam Eaton, who should be a solid center fielder and leadoff man. The White Sox also swapped Addison Reed to plug a hole at third base with Matt Davidson, another potential 20-homer guy.

Chicago upgraded its lineup and has enough pitching depth to weather the loss of the arms it surrendered. While these moves won't make the White Sox an instant contender, they are a needed step in the right direction.

What's your take on left-handers Lewis Thorpe (Twins) and Daniel McGrath (Red Sox) as prospects? Whom do you consider the top prospect from Australia?
-- Josh G., Somerville, Victoria, Australia

Though Grant Balfour made the All-Star Game in 2013 -- and he's one of 26 Aussies to appear in the big leagues in the last 25 years -- there isn't an obvious next wave of Australian talent in the Minors right now. Thorpe is the best Australian prospect, and McGrath would rank right behind him. But neither has advanced to a full-season league yet.

Thorpe signed for $500,000 in July 2012 and led the Rookie-level Gulf Coast League with 64 strikeouts in 44 innings while making his pro debut at age 17. Since turning pro, he has added about 50 pounds (up to 215) on his 6-foot-1 frame and 4-5 mph to his fastball, which now ranges from 88-95 mph. He throws a lot of strikes, and while his changeup is better than his breaking stuff, he has made some strides with his curveball and slider.

McGrath signed for $400,000 in February 2012. He broke into pro ball this summer as a 19-year-old, fanning 65 in 53 1/3 innings between the GCL and the short-season New York-Penn League. The 6-foot-3, 210-pounder usually works at 86-89 mph with his fastball, and like Thorpe, his changeup is more advanced than his breaking ball.