Pagano thanked Arians for the "masterful" job he did in leading the team to the NFL playoffs.
"You carried the torch and all you went out and did was win ballgames," Pagano said.
Indianapolis (10-5) has been waiting months for this day, and last week Arians called Pagano's impending return the best Christmas gift the team could get.
Pagano began the first of three rounds of chemotherapy Sept. 26, after the team completed its final practice during a bye week.
When the Colts returned to their practice facility Oct. 1, they were told Pagano had cancer and was taking an indefinite leave.
Arians, a prostate cancer survivor, immediately established the goal: Play long enough so Pagano could return to the sideline this season.
If all goes well at practice this week, Pagano will likely be on the sideline calling the shots Sunday against AFC South champion Houston in the regular-season finale. It would be the first time Pagano has been making game-day decisions since Jacksonville scored a last-minute touchdown on an 80-yard TD pass in Week 3, handing Indy it's only home loss this season.
When players arrived at training camp in August, they handed out T-shirts that showed where the so-called experts figured they would finish this season: The NFL's worst team again.
But with Sunday's 20-13 victory at Kansas City, Indy clinched its first playoff spot of the post-Peyton Manning era and Arians tied the league record for most wins after a midseason coaching change (nine). Indy is the fourth team in league history to win two or fewer games one season and 10 or more the next and became the second team in league history to lose 14 or more games one season and win 10 or more the next -- joining the 2008 Miami Dolphins.
He was in contact with players and coaches primarily through phone calls and text messages, watched tapes of practices and games on his computer, attended three home games and sometimes showed up at the team complex. He occasionally gave pregame or postgame speeches throughout his recovery.
On Nov. 5, Pagano's oncologist, Dr. Larry Cripe, said the illness was in complete remission, though Pagano still had to complete two more rounds of chemotherapy. The last round ended the first week of December. Last Thursday, Cripe said he gave Pagano medical clearance to return to the team. Cripe said he was putting no restrictions on what Pagano could do, only that he advised Pagano, as he does with other patients, to scale things back if necessary
Copyright 2012 by The Associated Press