Some fans were questioning why the Colts would choose to give Jacoby Brissett a new contract before he actually plays a down in 2019. Brissett was entering the final year of his cheap rookie deal (just $2M), which is quite a bargain, regardless of how effective he was going to be. However, there are several good reasons for doing what Chris Ballard & Co. did yesterday:
Shows their confident in the young starter
Chris Ballard and Frank Reich have claimed all along that Brissett is a Top 20 starter, so why not give him Top 20 money? This deal replaces Brissett's existing contract and instantly makes him the 19th highest-paid quarterback in the league. It also shows Brissett through the team's actions - not just their words - that he's their guy.
Gives the Colts more time to take a look
Let's say Brissett blows up this year and becomes a legitimate, upper-half NFL starter (or better!)... think about the kind of deal he would've commanded in free agency next year. This protects the Colts in case the best-case scenario plays out and puts Brissett under team control for an extra year. Something else to note here: it helps the team avoid having to use the franchise tag on Brissett in 2020. They just used a franchise tag without really using a franchise tag.
The Colts have a ridiculous amount of cap room
Indianapolis was entering the season with the most cap space in the NFL (nearly $60M before the Brissett deal was completed), and depending on the structure, as Joel Erickson of the IndyStar pointed out, the team could push a majority of the $20M guaranteed toward their 2019 cap. That would make the contract easier to absorb if Brissett were to tank this season. And, even if he were to tank, so what? The Colts are only on the hook for 2020 and can draft his replacement this Spring.