MLB executives, owners and agents told ESPN.com’s Jayson Stark that they see Albert Pujols agreeing to an extension with the Cardinals between now and Spring Training. And the deal will likely make Pujols one of the richest players in baseball history. The sides figure to agree to a deal worth $240MM over eight years, in the estimation of Stark’s sources.

Pujols, who is scheduled to hit free agency after the season, will stop negotiating with the Cardinals once Spring Training begins. And scuttlebutt from other clubs suggests Pujols and agent Dan Lozano will start by asking for a ten-year, $300MM deal.

But Cards GM John Mozeliak is unlikely to want to pay the first baseman $30MM per season while he’s in his early forties, so Pujols’ deal may not be worth more than Alex Rodriguez’s record ten-year, $275MM contract.

If Pujols hits free agency, interest will be widespread. Even clubs like the Yankees and Red Sox, who have elite first basemen, could have interest in Pujols, according to one executive. Teams like the Cubs, Dodgers and Mets could also have interest, though there’s a good chance the first baseman won’t hit the open market.

I previewed a potential extension for Pujols earlier in the month.