A.J. Burnett takes the hill against Alfredo Simon, whose major league career consists of 13 innings (all last year, including one start and three relief appearances). He's 28, so he's no prospect, and has underwhelming minor league numbers. Like Al Aceves, he was signed out of the Mexican League last year. He did, however, have a good spring, pitching in four games to a 1.13 ERA.
Burnett could have a rough day. The only Baltimore hitter he's dominated is Aubrey Huff. Nick Markakis, Melvin Mora, Ty Wigginton, Brian Roberts, Luke Scott and even Adam Jones have all had at least moderate success against Burnett.
His career ERA vs. Baltimore is 4.97, yet his record is a robust 7-1. He must've had a lot of run support. Last year he was just awful, pitching only 14.2 innings in three games due to a 9.82 ERA.