Northern Ireland boss Michael O'Neill believes former Rangers striker David Healy still has "loads to offer" despite leaving the free agent out of his 20-man squad for next week's World Cup qualifying home clash with Russia.

Healy, his country's record scorer with 36 goals, is currently unattached having been released by Bury in May.

The 34-year-old is among three players without a club that O'Neill has opted to leave out of his party for the rearranged Group F game at Windsor Park next Wednesday, along with defender Chris Baird, let go by Fulham this summer, and ex-Celtic midfielder Paddy McCourt.

O'Neill said: "David still has loads to offer I believe. I think if he finds a manager who has faith in him and gives him the opportunity, he is more than capable of scoring goals for a club and still at international level.

"I think it is difficult for player who is unattached."

O'Neill is still searching for his first victory since being appointed as Northern Ireland boss in December 2011, having overseen a total of nine fixtures.

And he thinks his team - who drew 1-1 in Portugal in October - can thrive as the underdogs next week.

"We are playing one of the top sides in Europe and I believe the strongest team in the group," O'Neill said.

"That tends to be when Northern Ireland are at their best and the players have everything to gain."