It's 3 weeks til RG. Any serious surgery will ko her for that tournament.
Let's speculate that Martina had a foot that was say, 90% healthy. She played Hamburg and discovered that the foot, while not so bad she couldn't play, was bad enough that she had very little chance of winning Berlin. Or anything else til it healed. But she COULD play on it and beat anyone outside the top 50.
If she withdraws from Berlin to give herself a chance to heal before Roland Garros, is that using an injury as an excuse to withdraw or not? Given that she COULD play, just at a sub-par level.
(BTW, I'm writing this with a pulled calf muscle that, if I wrap it, I COULD play tennis on, but not as well as usual. Wonder what I would do in that situation...)