A seed island is required for destabilizing the neoclassical tearing mode (NTM), which degrades confinement in long sustained, high confinement, high beta plasmas. The seed island formation due to an MHD event, such as a sawtooth crash, is investigated by applying an improved boundary layer theory of forced magnetic reconnection. This improved theory introduces non-constant-ψ matching and reveals the complicated nature of the reconnection described by two reconnected fluxes. In the initial evolution, these reconnected fluxes grow on a timescale consisting of the ideal timescale, the MHD event timescale and the resistive kink timescale. The surface current is negative, Δ'(t) < 0, to be consistent with NTM theory. The theory also yields a new integral equation which includes the typical timescale of the resistive kink mode and allows us to investigate the time evolution of the seed island at time t ∼ τA S1/3.