Not really. The Origin of Species was published in 1859. Mendel’s paper appeared in 1866. Once the Origin appeared, although inheritance of acquired characteristics hung around for a bit (not being a real threat to the fundamentals of Darwinism) Lamarckism in general was no longer a contender. It just did not explain the crucial facts (see post #18, above). Darwin and his allies did not need Mendel to refute Lamark.
Mendel’s importance has been much overrated, anyway. His vicissitudes make a neat story that served as a useful rhetorical trope for the real founders of genetics in the early 20th century. It is cool to have an unjustly neglected intellectual precursor. It helps to get you proper respect. That is the most of it, really.