He faced the Mets on May 18th, so here is the scouting report, with an update on his current stats at the end.
The 24-year old Kris Medlen made his major league debut last year in May, after going 5-0 with a sub 1 ERA in AAA (he got the promotion before T Hanson). The converted college shortstop (drafted in the 10th round in 2006) worked exclusively out of the bullpen his first two years, but excelled in the Arizona Fall League and the Braves moved him to the starting rotation last year. He appeared in 37 games for the Braves last year, starting four games, and had a 4.26 ERA and 1.40 WHIP. He pitched versus the Mets three times in relief last year, throwing 5 1/3 shutout innings, allowing five hits and one walk, striking out five.
The 5'11" Medlen throws 90-94, but usually settles into 90-91 when he's starting. He features a plus change-up (81 mph), and also mixes in an average curve-ball (80 mph). His fastball and change-up have been very successful in the big leagues. His strikeout rates have been outstanding in the minors (10 K/9), and is 9.2 K/9 in the majors, while having decent walk rates (4.0 W/9 last year, but 1.2 W/9 this year). He has fly ball tendencies.
So far this year, he's made 13 relief appearances, and one start vs the Phillies. He's thrown 23 innings, allowed 25 hits and only three walks (outstanding) with 20 strike outs. His ERA is 2.35 and a 1.217 WHIP. Versus the Phillies he lasted 4 1/3 and allowed nine hits and one run, throwing 88 pitches.
UPDATE AUGUST 4th: He faced the Mets on May 18th and threw 6 1/3 innings,allowing only 2 runs (2 home runs by Ike and Frenchy) and 6 base-runners, while striking out 6. He made 9 starts after that, before returning to the bullpen around the all-star break to decrease his workload, including an inning appearance on July 11th vs the Mets, where he threw a scoreless inning, but allowed a hit and a walk. His last two starts he's thrown 11 innings, and let up 8 earned runs. He's currently 6-2 (103 innings, 13 starts, 17 relief appearances), 3.66 ERA, 1.20 WHIP. His K/9 rate is 7, and walking 1.74/9. He's let up 13 home runs already. He hasn't thrown 7 innings in a game since June 3rd, and hasn't thrown 100 pitches since June 25th.
Recap: The scouts are worried that his diminutive frame will not be able to withstand the stresses of being a starting pitcher full-time. He has the upside of a #3/4 starter. He throws 1st pitch fastball 74% of the time, and uses his plus change-up as his strike out pitch.