Final answer:
The sentence missing a comma is: 'The player, who had lost in the previous match managed to pull off a win.' The comma should be placed after the word 'player' to separate the introductory clause 'who had lost in the previous match' from the main clause 'managed to pull off a win'.
Step-by-step explanation:
The sentence missing a comma is: The player, who had lost in the previous match managed to pull off a win. The comma should be placed after the word 'player' to separate the introductory clause 'who had lost in the previous match' from the main clause 'managed to pull off a win'.
The sentence that is missing a comma is: 'The player, who had lost in the previous match managed to pull off a win.' The correct version of the sentence with the missing comma inserted would be: 'The player, who had lost in the previous match, managed to pull off a win.' This comma is essential as it sets off the nonrestrictive clause ('who had lost in the previous match') which provides additional information about the subject of the sentence but is not essential to its meaning.