The FastTracKer (FTK), a hardware dedicated processor, performs fast and precise online full track reconstruction at the ATLAS experiment, within an average latency of few dozens of microseconds. Before production of the final system for tracking in high-occupancy conditions with the best of available technology, we plan to use existing prototypes of the FTK hardware to exercise its functions in the ATLAS environment. We describe the “baby FTK”, consisting of a few hardware elements implementing the first stages of the system, and discuss our plans to grow the system into a full-functionality FTK “vertical slice” covering a small projective wedge of the detector. We report on the performances and structure of the “baby FTK”, including the pixel/strip hit clustering (clustering mezzanine), hit organization and distribution (EDRO) and the Associative Memory pattern recognition function. We describe briefly also the possible future evolution including the addition of the Track Fitter.