Martinez said: "You can see with Lacina's height - he is an inch taller than Peter Crouch - that he is a unique footballer. But his size may give you the wrong impression of the way he is.
"Technically he is very gifted, he doesn't play just as a normal target man and he gives you a different dimension up front. He is very quick and is a real athlete.
"Those aspects make him a little different and he is a footballer who will bring us a lot."
He added: "He's got great awareness of what's around him and a very clinical eye. In the Russian League he had a goal ratio of one every two games and that shows he is a natural goalscorer.
"He is coming back from Russia after a period with a few injuries and he wants to get back showing a real desire of what he can do.
"Now we just need to be a little bit patient to make sure he is fully fit."