The forward has been attracting interest from Huddersfield Town and Peterborough United but has an option of another year at Coventry City.
"The clause in my contract has happened," Simpson said to the CT. "I have had a letter saying that the club want to take that option up so I am pleased that they feel so highly of me to give me that extra year.
"So I have got one more year left and I can hopefully sit down with the chairman to maybe discuss new terms and we will see what happens in the next three or four weeks."