May 19, 2010 8:20 AM EST

Nationals pitching prospect Stephen Strasburg has a 1.06 ERA in the minor leagues, but he'll remain there for now.

There have been questions about why Strasburg hasn't been promoted after draft-mate closer Drew Storen was earlier this week.

"I know what I have in mind with him," general manager Mike Rizzo said.

"I'm not going to say if it's close or far away, but let's face it - this guy is a special, unique performer. Whenever we err, we need to err on the side of caution with him. Because we're looking long-term with the player. Being a starting pitcher, being a young 21 year old ... we're going to be careful with him. I know in my mind what the development plan is for him. I have a window. I know when he's going to come up. In this job, you're open for criticism, whether you do it now or you do it later. You either held him a month too long or put him a month too soon. I've got to look in the mirror, and I've got to develop him the way I believe he needs to be developed. That's why I'm the general manager of the team, because I have developed players in the past, and that's how I got the job. I feel comfortable with his developmental schedule. I think it's the right schedule, and I think it's best for him long-term."

The Washington Post writes that he'll likely debut on June 4th.

Via Washington Post