INDIANAPOLIS — It was only a matter of time. And now the deal officially is getting done.

The Indianapolis Colts announced today that they have agreed to terms on a contract extension for veteran left tackle Anthony Castonzo. Terms of the deal were not disclosed.

Castonzo, who will be 32 by Week 1 of the 2020 regular season, told reporters in early-January that he was going to take some time to consider his future plans. Set to become an unrestricted free agent at the start of the new league year, which is scheduled to begin at 4 p.m. ET Wednesday, Castonzo said he was realistically deciding between either re-signing with the Colts for a 10th season or retiring.

He stayed in touch with the Colts and general manager Chris Ballard, and on Feb. 25 Ballard told reporters that Castonzo had in recent days told him that he intended to re-sign with the team.

Castonzo formally agreed to terms today, allowing the Colts to turn their attention to more pressing matters with free agency and the NFL Draft just around the corner.

"We think a lot of Anthony Castonzo," Ballard said back in January. "I do think Anthony Castonzo's playing at a high level still, I think he's got three or more more years of high-level play at left tackle."

Castonzo is coming off perhaps the best season of his career. The former first-round pick out of Boston College was one of just two Colts players to play all 1,077 offensive snaps on the year, ranking as Pro Football Focus' ninth-best offensive linemen in the NFL; his pass-blocking grade of 81.3 was 13th best among all qualifying offensive linemen, and sixth among tackles, while his 70.2 run-blocking grade ranked 23rd among linemen and eighth among tackles.

In total, Castonzo allowed just three sacks and five quarterback pressures all season, according to PFF, and was named a Pro Bowl alternate for the first time in his career. He was also named to PFF's 2019 All-Pro team as a second-team selection at left tackle.

Perhaps most importantly, Castonzo's strong play protecting the quarterback's blindside allowed head coach Frank Reich to utilize potential extra blockers in other roles.

"That position, I don't take it for granted," Reich told reporters Feb. 25 at the NFL Scouting Combine. "Every week when we're protection gameplanning, as an offensive playcaller and gameplanner, you've got to think, 'I don't have to worry about chip-helping Anthony Castonzo. He can handle whoever it is over there one-on-one.' I can't begin to explain what an advantage that is schematically in the pass game not to have to help protect him all the time. So, good to have him back.

"What you're afforded is, boom, now you got the (running) back out and it puts more pressure on the defense," Reich continued. "So (Castonzo) gets very little help. He tells me that all the time, he lets me know — but he'll be compensated accordingly."

Castonzo's return also means the Colts will field the same starting five offensive linemen for a third straight season, and second full year in a row. Indy in 2019 had all five starters up front — Castonzo at left tackle, Quenton Nelson at left guard, Ryan Kelly at center, Mark Glowinski at right guard and Braden Smith at right tackle — start all 16 games together.

The unit overall ranked as PFF's third-best offensive line in the NFL.