Allen has been linked with both the Seahawks and the Dallas Cowboys since seeing his contract with the Vikings expire, although the Cowboys are understood to have withdrawn their interest due to high contract demands.
The 31-year-old visited the Seahawks yesterday with the deal expected to be agreed upon, although he has since confirmed that nothing has yet been signed and that he is considering the offer.
Allen is understood to have a price in mind that he will need to be offered in order to stop him retiring from the NFL before the 2014 season.
"We are heading home and will consider their offer and I'll make my decision this weekend," he said in a text message following his meeting with the Seahawks, according to ESPN.
Allen has recorded at least 10 sacks in seven consecutive seasons and has 128.5 overall in his career, the 12th highest total in NFL history.