The IMPD said Sanchez was arrested at the hospital on suspicion of battery with injury, unlawful entry of a motor vehicle and public intoxication. No further individuals are being sought by detectives. The Marion County Prosecutor's Office will make the final charging decision, the IMPD said.
Sanchez is still hospitalized and has not yet been booked. Earlier Saturday, Fox Sports said in a statement that Sanchez is recovering and in stable condition.
"We are deeply grateful to the medical team for their exceptional care and support. Our thoughts and prayers are with Mark, and we ask that everyone please respect his and his family's privacy during this time," Fox Sports said in its earlier statement.
The IMPD earlier said that it was investigating an incident between two men that took place at approximately 12:30 a.m. Saturday in the popular downtown nightlife Wholesale District, next to the Indiana statehouse. The IMPD did not identify the men in its earlier statement but said one man received lacerations while the other man received injuries consistent with stab wounds.
Police said neither man was a local resident and called it an "isolated incident between the two men and not a random act of violence."
Sanchez, 38, was scheduled to be part of the broadcast crew for Sunday's game between the Las Vegas Raiders and Indianapolis Colts at Lucas Oil Stadium, but will no longer work the game. He appeared on ABC and ESPN for two years before joining Fox Sports as a game analyst in 2021.
The Long Beach native played eight seasons in the NFL after being selected fifth overall by the New York Jets in the 2009 draft out of USC. He helped the Jets to back-to-back AFC Championship Game appearances in his first two seasons.
He passed for 3,207 yards and 34 touchdowns while leading the Trojans to a 12-1 record during his junior year, which included a victory over Penn State in the 2009 Rose Bowl.
Sanchez also played for the Philadelphia Eagles, Dallas Cowboys and Washington, the team he last appeared in a regular-season game for in 2018.
The Jets and several of Sanchez's former teammates posted messages of support on social media on Saturday.
"Sending our thoughts and love to Mark Sanchez and his family. Hoping for a speedy recovery, 6," the Jets said, using Sanchez's former jersey number.
"Send prayers up for my former teammate Mark.. sucks so much to see this," Kerry Rhodes wrote.
"So sad. Pray for his recovery," Nick Mangold wrote.
The Associated Press and ESPN contributed to this report.