Castonzo agreed to a four-year extension that runs through the 2019 season, the Colts' official site reports.

Castonzo has started 56 consecutive games as the Colts' left tackle.

Colts exercised LT Anthony Castonzo's fifth-year club option for 2015.

The Indianapolis Star reported earlier this month that Castonzo's option is worth $7.4 million. The move keeps him under team control for a bargain $8.9 million over the next two seasons. The No. 22 overall pick of the 2011 draft, Castonzo has started all 16 games each of the past two seasons. He's been a solid, if far from dominant, protector on Andrew Luck's blindside.

The Colts are expected to exercise LT Anthony Castonzo's fifth-year club option of $7.4 million in 2015.

The move will keep Castonzo signed for a total of $8.9 million over the next two seasons. Castonzo graded out as a top-20 left tackle by Pro Football Focus, but has struggled in pass protection -- allowing 39 quarterback hurries in 2013. The deadline for teams to exercise fifth-year options is May 3.

Colts LT Anthony Castonzo (knee) is expected to play in Week 1.

Castonzo sprained his left MCL in the preseason, but the injury was "mild" and he'll return to practice on Thursday. Indianapolis' offense will be at near-full strength as it prepares to take on the Raiders' sieve-like defense.

Colts LT Anthony Castonzo has been diagnosed with a sprained left MCL.

Castonzo's sprain is considered mild and the Colts are hopeful he'll be back for Week 1. In the meantime, they'll start Joe Reitz at left tackle in the preseason finale. Castonzo was ProFootballFocus' No. 32 overall tackle last season, but was 62nd in terms of pass blocking. Andrew Luck took 41 sacks in 2012 -- only Aaron Rodgers (51), Philip Rivers (49) and Andy Dalton (46) took more.

Colts LT Anthony Castonzo underwent postseason surgery on his foot.

Castonzo battled through a left high ankle sprain as a rookie, so we suspect the surgery was related to that. He isn't participating in pre-draft workouts. Castonzo projects as Indianapolis' Opening Day starter at left tackle.

Colts rookie LT Anthony Castonzo has unofficially given up six sacks in nine games played this year.

Castonzo missed four games due to an ankle injury. The six sacks allowed aren't unruly, but it's not what the Colts expected after using the No. 22 overall pick on Castonzo in April. "He's making progress, but part of that in this league is you're going to have some tough days," coach Jim Caldwell said.

Colts LT Anthony Castonzo (ankle) has had no setbacks in his return to practice this week.

Castonzo expects to return Sunday against the Falcons after missing three games. Jeff Linkenbach will swing back to right tackle, and RG Ryan Diem is also expected to play for the first time in a month. It's a boost for Curtis Painter and the passing game.

Colts LT Anthony Castonzo (ankle) returned to a light workout Monday.

It's Castonzo's first practice of any kind since he suffered a high-ankle sprain on Oct. 3. His potential return for Sunday's home game with the Falcons would be a little boost for Curtis Painter and the passing game.

Colts LT Anthony Castonzo (ankle) has been downgraded to out for Week 8.

Castonzo has now missed four straight games, but is considered a good bet to return in Week 9. The Colts will also be without RT Ryan Diem and LG Joe Reitz against the Titans, once again leaving them extremely thin along their offensive line.

Colts LT Anthony Castonzo says he will return from his sprained left ankle "sooner rather than later."

Castonzo has missed three games with the injury. The Indianapolis Star suspects he will return next week or the week after. The Colts offensive line is a train wreck heading into Sunday's game with the Titans.

Colts LT Anthony Castonzo (ankle) is expected to miss "at least a few weeks," according to the Indianapolis Star.

Yikes. Castonzo wasn't dominating, but losing the No. 22 overall pick is going to turn this Colts' offensive line into an unmitigated disaster. Backup left tackle Ben Ijalana (ACL) is already on injured reserve, leaving Curtis Painter's blind side extremely vulnerable. The plan for now is to get Ryan Diem (ankle) back healthy and starting at right guard, thus kicking Jeff Linkenbach to left tackle. A street free agent or third-stringer will end up starting on the right side.

According to the Associated Press, Colts LT Anthony Castonzo (ankle) is "likely to miss" Week 5 against Kansas City.

It's a major concern for Curtis Painter, particularly after backup LT Ben Ijalana went on I.R. Wednesday with a torn ACL. Castonzo may have a high ankle sprain. Look for the Colts to start Jeff Linkenbach at left tackle, where he'll square off with a red-hot Tamba Hali. Mike Tepper, Michael Toudouze, and Quinn Ojinnaka would all be candidates to step in on the right side.

No. 22 overall pick LT Anthony Castonzo was on crutches after Monday's game, and his injured left ankle was in a walking boot.

The seriousness of backup Ben Ijalana's back injury is unknown, and as a result RT Jeff Linkenbach was kicked over to LT and Mike Tepper went from the practice squad to RT in less than 24 hours. Aside from having a quarterback with too many problems to name here, Colts skill position players could be working behind one of the league's worst lines.

Rookie LT Anthony Castonzo left Monday's game with an ankle injury and is questionable to return.

We'll update you as we learn more, but losing Castonza for any length of time would be a decent-sized blow to the Colts. They're banged up right now with RG Ryan Diem (ankle) out, as well.

No. 22 overall pick LT Anthony Castonzo "held his own" in the Colts' preseason opener on Saturday.

Most of Castonzo's playing time came against the Rams' second team, but he did show quick instincts and good strength. That's great news for the Colts, who were all but forced to name Castonzo their starting blindside protector when Charlie Johnson bolted for Minnesota.

Colts agreed to terms with No. 22 overall pick LT Anthony Castonzo on a four-year contract.

One mid-July report suggested the Colts were no longer confident in Castonzo as the Week 1 blindside starter after missing offseason workouts. With Charlie Johnson now in Minnesota, they don't have much of a choice. A 54-game starter at Boston College, Castonzo was considered the most pro-ready lineman in the draft. He should be an upgrade on Johnson regardless.

According to the National Football Post, the lockout has "dimmed the hopes of the Colts' coaching staff" for first-round pick Anthony Castonzo.

When Castonzo was taken at No. 22 overall in April, the Colts believed he would be able to immediately step in as their starting left tackle, but no longer think so after an offseason without OTAs. The Colts' 2010 left tackle Charlie Johnson is an unrestricted free agent, but could be brought back to man the blindside early before being shifted to guard.