The Indianapolis Colts plan to release quarterback Peyton Manning and were making arrangements, barring a last-minute reversal, to announce the move Wednesday, several people familiar with the situation said Tuesday.

Dialogue between Colts owner Jim Irsay and Manning was continuing, but the team and its longtime quarterback were prepared to part ways, said the sources, who spoke on the condition of anonymity because the decision had not been confirmed publicly. The Colts were making plans for a formal announcement with both Irsay and Manning involved, people familiar with the plans said.

The move is likely to become official soon after that announcement. Manning, the only four-time most valuable player in NFL history, then would become an unrestricted free agent and would be free to sign immediately with any NFL team.

The Washington Redskins appear to be among the teams most interested in trying to land him.

Manning’s departure from the Colts, first reported by ESPN, has been widely expected in recent months after Irsay conducted an offseason house-cleaning that included the firing of Coach Jim Caldwell, top football executive Bill Polian and General Manager Chris Polian.

Manning missed all of last season after undergoing a series of neck surgeries. The Colts would have to pay him a $28 million bonus if he is on their roster Thursday, and they hold the first overall pick in the NFL draft, which they are expected to use to select Stanford quarterback Andrew Luck.

Manning’s neck injury and his hefty roster bonus made his once-unthinkable departure appear increasingly inevitable.

“As a guy that welcomed Peyton to Indy in [’98] it is surreal to think he’ll be playing somewhere else,” former Colts linebacker Bertrand Berry wrote on Twitter. “All that said most player[s] deal with it!”

The Colts and Manning’s representatives declined to comment on the matter Tuesday.

The Indianapolis Star reported that Manning and Irsay were sharing a flight from Florida to Indianapolis and would continue talking. But it did not appear there was a compromise in the works that would keep Manning with the Colts. Irsay said recently that the team would be willing to retain Manning with a reduced contractual commitment, but it did not appear Tuesday that Manning was interested in accepting that arrangement.

Manning, who will turn 36 this month, appears intent on finding a new team with which he can attempt to make a successful return and pursue a second Super Bowl title.

The Redskins, Miami Dolphins, Arizona Cardinals, New York Jets, Seattle Seahawks and Kansas City Chiefs are among the teams most often mentioned as possible contestants in the Manning sweepstakes. The Redskins have more than $40 million in estimated space under the salary cap, and Manning gets a jump by hitting the market nearly a week before teams can begin making deals with unrestricted free agents Tuesday.

A person familiar with Manning’s rehabilitation said last week that Manning had been throwing well recently. Orthopedic surgeon Robert Watkins has pronounced Manning’s neck sufficiently healed for him to resume his football career once his nerves regenerate enough to give him adequate strength in his shoulder and right arm.

The Redskins are looking to replace Rex Grossman at quarterback. Their two leading options are signing Manning or attempting to trade up with the St. Louis Rams for the second overall choice in the draft, which they could use on Baylor’s Heisman Trophy-winning quarterback, Robert Griffin III.

There are indications that the Rams are willing to trade their draft pick sooner rather than later, so it’s possible that the Redskins will resolve their quarterback situation even before free agency opens. The Redskins appear prepared to meet the Rams’ asking price for the draft pick.

If the Redskins are unsuccessful in both maneuvers, they could sign a veteran free agent such as Kyle Orton and seek a young quarterback such as Ryan Tannehill of Texas A&M in April’s draft. Green Bay Packers backup Matt Flynn, who appears to be coveted by a number of quarterback-needy teams, will also be available in free agency.

Manning has thrown for 54,828 yards and 399 touchdowns in 13 seasons with the Colts, who selected him with the top overall choice in the 1998 NFL draft. He threw for 4,700 yards and 33 touchdowns with 17 interceptions, when he last played in the 2010 season. He had never missed an NFL start until last season, his 14th year with the Colts.