With Ferrer unable to add any points to his total unless he reaches the final in Austria, Murray climbed into ninth place with a straight-sets win in the quarter-finals on Friday.
The pair could meet in Sunday's final at the ATP 250 hard-court event in what would be a straight fight for qualifying points.
Murray was on the attack from the start and, although he was unable to convert either of the break points he had in the opening game, eventually he forged ahead.
With the score at 2-2 the Briton broke through the Struff serve, giving him the momentum to go on and claim the final four games of the set to stake an early claim.
Struff had only managed to win two points on Murray's serve going into the second set, but he immediately improved on that with a competitive second game, only for Murray to hold firm.
He did break him in the fourth, though, but Murray was not behind for long as he broke twice to set up a semi-final meeting with Viktor Troicki.
The Serbian had to battle for his place in the last four as the opening two sets went to a tie-break, both players winning one apiece to take the match into a decider.
It was there that Troicki pushed ahead, winning the final three games of a match that saw 22 aces to secure 7-6 (7-4) 6-7 (2-7) 6-2 triumph.
Ferrer's hopes of making the top eight for the finals in London remain intact, though, as he overcame the big-serving Ivo Karlovic.
The Croat served 17 aces in the match against the top seed, but Ferrer was able to withstand the pressure to prevail 7-6 (7-5) 6-4.
He will need to beat Philipp Kohlschreiber in the semi-finals to start earning points for London, though, after the fourth seed progressed from an all-German quarter final against Benjamin Becker.
Kohlschreiber served 11 aces and saved nine break points in the match before running out 6-4 7-6 (7-3) winner.