We analyze s-wave pion-nucleon scattering in a unitarized chiral effective Lagrangian including all dimension two contact terms. We find that both the S(11)(1535) and the S(11)(1650) are dynamically generated, but the S(31)(1620) is not. We further discuss the structure of these dynamically generated resonances. (c) 2011 Elsevier B.V. All rights reserved.