WESTFIELD, Ind. -- The Indianapolis Colts have signed right tackle Braden Smith to a four-year, $72.4 million contract extension, with $42 million guaranteed, a source told ESPN's Jeremy Fowler.

"We want to take care of our players," general manager Chris Ballard said earlier this week.

Smith, a second-round pick in 2018, spent the majority of his college career at Auburn playing guard. But the Colts developed him into a right tackle after selecting him, and he became the full-time starter at the position early in his rookie season. He's helped the Colts have one of the top offensive lines in the NFL, playing alongside center Ryan Kelly and guards Mark Glowinski and Quenton Nelson.

"I mean, yeah, anytime you work at a position for three years you are going to feel pretty good at it," Smith said in May. "I definitely feel comfortable and every day getting more comfortable getting the reps, getting the technique down and just keep improving every year."

Signing Smith is the start of what should be several contracts the Colts give out to what turned out to be an impressive 2018 draft class.

Darius Leonard, who has become one of the top linebackers in the NFL, is also in line to get an extension. He has 416 tackles, 15 sacks, seven interceptions and nine forced fumbles in three seasons.

Nelson, who was the No. 6 pick in the 2018 draft, has a very good chance of becoming the highest-paid players at his position when he does get his extension. Nelson has been named an All Pro in each of his first three seasons in the NFL.

"Let me say this, we've had a great back and forth," Ballard said. "[Director of football administration] Mike Bluem has done tremendous, as all the agents we've been working with. They've been tremendous. It goes back and forth. Getting these early extensions done are not always easy but we'll continue to work through it."