Everton manager Roberto Martinez has insisted that deadline-day signing Oumar Niasse is not a "back-up" for Romelu Lukaku.

The 25-year-old forward completed a move to Goodison Park on Monday from Lokomotiv Moscow for a fee of £13.5m.

Due to rumours that Lukaku is a summer target for Manchester United, there have been suggestions that Niasse could be a long-term replacement for the Belgian.

In Tuesday's press conference, Martinez insisted that Niasse will not play second fiddle to Lukaku.

"He is not back-up," the Spaniard told reporters. "He has his own ability and he is someone who can stretch a defence.

"He can cope with the physical nature of the Premier League. The last game in Russian league was December 10 - that was when their winter beak started - so the first thing is to get him back to full fitness.

"But he is really intelligent and he has a lot of assists. He is a striker who can fit in different formations."

Niasse is expected to make his debut at the weekend against Stoke City.