The 30-year-old forward has been the Lions’ most potent player in the past few months, and his three goals against the Dons in 2021 have caught the eye of new Aberdeen manager Stephen Glass.
The former Arsenal youth will be allowed to leave West Lothian due to a “gentleman’s agreement” between Martindale and the player, but the Livi chief expects a fee to be involved.
“I had a gentleman’s agreement with big JET. I’ve been open and honest about it, if JET could go over to foreign shores and pick up bigger money, he’s not getting any younger.
“With the finances at Livingston, there’s no way a player of that ability should be playing for Livingston, if I’m honest.
“I got him due to Covid. It took us a long time to get him up to speed, so I think everybody’s seen what he’s capable of in the last six weeks to two months.
“By JET staying in Scotland, I’ve also got a handshake with JET that we would command a fee if that was a possibility.
“JET’s agent has been dealing with that side of things but I know it’s been ongoing. I’ll pick that up this week.
“Would I love to see JET staying in Scotland? Yes, I would. Would it help Livingston Football Club financially if he stays in Scotland? Yes, it would.
“They’re not getting him for nothing!"
Livingston needed to defeat St Johnstone to leap above the Saints and claim fifth spot in the Premiership, but the goalless draw at McDiarmid Park resulted in them finishing sixth and missing out on a potential Europa League berth.
However, Martindale admitted that outcome is a relief as well as disappointing, with Livingston currently unable to compete in Europe due to licencing restrictions emanating from not having their youth academy up and running.
"Let's be honest, we lost fifth place by two goals,” said Martindale. “The six goals we lost at Parkhead is probably where we've let ourselves down slightly. Disappointed but, on reflection, it's been a fabulous season and the boys have to take massive credit for that.
"There was a part of me with trepidation if we finished fifth and the club couldn't have gotten into Europe, it would've brought a massive negative to us. There's relief and disappointment.
"It's down to club licencing, we've not got a youth academy. It was meant to get started up last March/April, but then Covid hit and part of the UEFA criteria is having a youth academy through the SFA. I'll be honest, it's probably a year too early. It's something we have been working on but finances, fans returning to stadiums, it's been extremely difficult to do that, and kids' football has only returned recently. There were loopholes in the UEFA regulations that potentially could have sneaked us through the back door if we'd finished fifth, but part of me thinks we wouldn't have made it and that would've been a massive negative.”