Having scanned the replies to this thread, I think a few people are guilty of a selective memory regarding Johnson, and do him a disservice to say he's been just a luxury, ornamental player since are return to the Championship - which isn't true.
He was electric in League One, no doubt about that, but I think his contribution in this league is often understated. He was superb for us in the first half of our first season back at this level, and almost our only creative outlet in a direct and one dimensional team.
His goals return from August - November 2015 probably kept Grayson his job, and PNE above the drop zone. His form did tail off towards the end of that first season, to be fair. Likewise, he was important at the beginning of our second season back, and a key part of our resurgence from around September onwards after a poor start. Again, it seemed like his form tailed off towards the end of that season, but so did the team's as a whole.
Maybe I'm being too kind to Johnson, I have a soft spot for him because he's a good footballer and has so often provided the spark of quality in hard working if unspectacular sides under Grayson/Neil. If we can find a place to accommodate him, and he acquiesces to work a bit harder off the ball perhaps, then I still think he has more to offer.