The first Test between England and West Indies is due to get underway on March 8 in Antigua.
Robinson suffered a back spasm as he pulled up midway through an over during a warm-up match against a Cricket West Indies President's XI. He couldn’t take part in training on Sunday (March 6).
With Mahmood finding a place in a 12-man group, the visitors will now have to take a call whether to hand the Lancashire quick his Test debut in an all-seam attack or go with a premier spinner in Jack Leach.
Mark Wood, Chris Woakes, and Craig Overton are likely to form the pace attack after veteran campaigners James Anderson and Stuart Broad were dropped from the squad following the Ashes 2021-22 humiliation.
"Ollie is a talented bowler -- naturally he'll be a big miss," Woakes said in comments carried by the BBC.
"He's shown in his short Test career so far that he's certainly got the skills and the ability to do good things in the format. At the same time, it gives people opportunities."
The tourists will take a call on the final XI at the toss in Antigua’s Sir Vivian Richards Stadium.
England Squad:
Joe Root (captain), Jonny Bairstow, Zak Crawley, Ben Foakes (wicketkeeper), Dan Lawrence, Jack Leach, Alex Lees, Saqib Mahmood, Craig Overton, Ben Stokes, Chris Woakes, Mark Wood
(With AFP inputs)