Based on the article, this shouldn't be a problem b/c he did not actually rupture the Achilles last year. He just strained it due to a Haglund's deformity (which he also had on the other foot and which caused his first Achilles injury). The deformity (bony growth on the back of the heel) has now been surgically removed, and it is not something that could recur, so he should be more explosive than ever.