See previous post on the same topic.

Listen to proponents of infant baptism (eg R.C. Sproul), it's unclear how circumcision and baptism are linked together.  It seems to be a concept foreign to the New Testament which then violates the protestant doctrine of sola Scriptura.

Another verse in Romans that highlights the point is found in Romans 4:10-11 "How then was it credited? While he was circumcised, or uncircumcised? Not while circumcised, but while uncircumcised; and he received the sign of circumcision, a seal of the righteousness of the faith which he had while uncircumcised"

Here Paul explains the circumcision came after Abraham's faith and that it was a sign of the seal of righteousness Abraham had because of his faith in the promise of God.  If circumcision is linked to baptism (which I just haven't found yet) it appears to be linked more closely to a believer's baptism, not infant sprinkling.  Abraham believed and was circumcised.  Just like the New Testment examples of believing then being baptized.

Note: At this point in my knowledge of the Scriptures, I don't see any linking between circumcision and baptism, but rather from circumcision to a spiritual circumcision of the heart.