 Complete the following phrase:  Benetton retained Alessandro Nannini and signed British rookie Johnny Herbert to replace Boutsen. However, Herbert was still recovering from severe foot injuries sustained in a Formula 3000 crash at Brands Hatch, and was eventually replaced by McLaren test driver Emanuele Pirro. Benetton continued as the de facto works Ford team, but had to make do with the Cosworth DFR-powered 1988 car, the B188, until the new HB-powered B189 was introduced at the 