The 45-year-old, whose Imps side narrowly missed out on promotion from League One last season when they suffered a playoff final defeat to Blackpool, revealed his testicular cancer diagnosis in a statement on Tuesday evening.
Appleton made clear he had received routine surgery, that doctors had identified a tumour early and that after a period of rest he hopes to be able to rejoin Lincoln’s preparations for another tilt at promotion within the coming weeks.
Among those to have sent messages of support on social media are Wednesday men Josh Windass and Chey Dunkley, the latter who played under Appleton at Oxford United.
Appleton also played and worked alongside Owls boss Darren Moore at West Bromwich Albion.
Dunkley wrote: “Not the news I wanted to hear, I wish you a speedy recovery gaffa... I know you will come back strong & I’ll see you live & well soon.”
Appleton’s statement to fans read in part: “A few weeks ago I was diagnosed with testicular cancer and will have the tumour removed this week. There are some quite scary words in that sentence, but this is quite a routine operation and the indications are that I should be back up and on my feet in no time.
“I do need to take a bit of a break, though, and after the surgery will be taking a couple of weeks to recover. This means I won’t be in the dugout for some of our pre-season games, but will be liaising closely with the coaching team as we continue preparations for the campaign.
“I’m not the sort of person who goes into much detail about these things, but I wanted to make sure you were all aware so you knew why I have to sit out a few games. There’s loads of advice out there about the early signs of cancer and what to look out for – if you have a lump or any other change please do get it checked out by a GP.”