Anthony Gardner partnered Ledley King in defence with Jermain Defoe partnering Keane in attack.
Rangers took the lead by early on through Nacho Novo, who took advantage of a slip by Gardner to sprint clear and fire past Robinson. Then came Keane’s injury.
The striker immediately signalled to the bench after Marvin Andrews blocktackled his attempted shot. He was carried off with a stabilising brace strapped to his right leg.
New Rangers signing Dado Prso made it 2-0 in first-half stoppage-time.