If they are smart enough to not value a career .720 OPS guy at $12 million might be a caution sign for us.
Kiermaier is currently 16% of the Rays payroll (he was 20% on Opening Day). In addition to Mike Zunino's 7 million dollar option, they have 13 players going to their first time (including Austin Meadows), and they have Glasnow going to Arb 3 while also likely missing a huge chunk of next season (they tried to trade him at the deadline before they announced he needed TJS).
While a normal team might not balk at Kiermaier for 12 million, the Rays' ownership simply won't provide the funds for him to take up 15-20% of the available payroll. Not when they have Manuel Margot capable of very good defense and similar offensive production at a fraction of the cost.
Couple that with a rather urgent need for 40 man roster spots, and the Rays have significant motivation to trade Kiermaier