Last season, Rodriguez notched a strikeout per inning, and his ERA would have been considerably lower than 4.38 if not for a 69 percent strand rate. However, Rodriguez relied on a higher rate of foul balls to maintain his K-rate, and meanwhile, his swinging strike rate fell from 13 percent in 2011 to 9 percent in 2012.

Unless Rodriguez can find a way to avoid contact at a higher rate, he could have a hard time maintaining a high strikeout rate. At risk of allowing more hits and runs, Rodriguez could be a very ordinary reliever this year -- and one not quite effective enough to hold down a prominent role.

Rodriguez tossed four scoreless innings over four appearances between Class A Brevard County and Nashville. He struck out seven, allowed one hit and walked three.

The Brewers have to decide this week whether to bring Rodriguez up to the majors or release him. The three-time All-Star struck out four over two innings at High-A Brevard County.

K-Rod will plan on pitching three times in Class A, and hope to be promoted to Triple-A Nashville to continue building his arm. The club has 30 days to make a decision on whether they want to promote Rodriguez to the major-league club.