Hearts boss Craig Levein has conceded that the speculation surrounding the future of Kyle Lafferty is having an effect on the striker.

Rangers are believed to be interested in re-signing the 67-time Northern Ireland international this summer, and have reportedly had a £200,000 bid rejected by Hearts this weekend.

Steven Gerrard's team are expected to return with an improved offer for the 30-year-old, and Levein has said that he is braced for "another month of nonsense" before the transfer window slams shut.

"As much as Kyle says it's not having an effect, I think it probably has," Levein told reporters. "The good thing is we only have another month of this nonsense until the transfer window closes."

Lafferty netted 38 times in 138 appearances for Rangers between 2008 and 2012 before joining Swiss outfit Sion, and he has also since represented Palermo, Norwich City, Caykur Rizespor and Birmingham City.

Last term, he scored 19 goals in 44 appearances for Hearts during a productive campaign.