But the potential hits to the Patriots coaching staff don't stop there.
The New England Patriots appear likely to lose both of the coordinators to head coaching jobs in the coming weeks.
However, critics of McDaniels will point out that his success could simply be a byproduct of the legendary combination of Bill Belichick and Tom Brady, whose success continues to transcend the sport of professional football. McDaniels is also a finalist for the Giants' head-coaching vacancy, though it looks like he's leaning toward joining Andrew Luck in Indianapolis.
The Colts franchise player could use much needed offensive continuity and an improved comfort zone, as he's already endured three offensive coordinators during his first six seasons in Indianapolis.
Vrabel, a former Patriots linebacker who is now the defensive coordinator for the Houston Texans, is also highly respected.
The Indianapolis Colts are still in the midst of their head coaching search following the firing of Chuck Pagano. But he's been eager to get another head coaching gig after his first go as head coach of the Denver Broncos lasted just two seasons.
With the Patriots, there is a good chance their season extends all the way through the Super Bowl so if McDaniels is to land the job, the Colts wouldn't be able to announce the hire until February 5, the day after the Super Bowl, at the earliest.