Discussions on a rookie contract extension for Phoenix Suns center Deandre Ayton ended ahead of a Monday deadline with no agreement, perishing without the franchise ever honoring the 2018 No. 1 overall pick's expectation of a five-year maximum contract offer, sources told ESPN.

Ayton, a key part of the Suns' run to the 2021 NBA Finals, held firm on wanting a full, five-year, max contract -- which would've been worth a guaranteed $172.5 million plus possible escalators -- but talks never progressed to the Suns making a formal offer on a max deal ahead of Monday's 6 p.m. ET deadline, sources told ESPN.

In recent weeks, Phoenix raised the concept of a shorter maximum contract deal -- perhaps over three or four years instead of the full five years -- but never formally made the offer or broached the idea again, sources said.

Phoenix now faces an uncertain future with Ayton. The franchise center is unhappy with the franchise's consistent stance to his representatives that the organization simply didn't foresee him as a max player -- regardless of which of his peers in the 2018 NBA Draft class earned max deals this offseason, sources said.

Ayton can enter restricted free agency next summer and sign an offer sheet elsewhere that would still allow the Suns' matching rights --- although it could be a four-year deal that includes an early termination after three years to become an unrestricted free agent. Ayton could also sign a qualifying offer to play out the 2022-2023 season and become an unrestricted free agent in 2023, which would risk the Suns losing a franchise cornerstone player for nothing.

Several of his 2018 NBA Draft classmates signed max deals, including Trae Young, Luka Doncic, Shai Gilgeous-Alexander and Michael Porter Jr. The Suns reached agreement with 2018 draft classmate, Mikal Bridges, on a four-year, $90 million extension on Sunday and a four-year, $43 million extension with guard Landry Shamet on Monday, sources told ESPN.

Many executives league-wide expected the Ayton max deal would be complete in short order this offseason, and now his possible emergence in the restricted free agent market could impact how team's navigate salary cap space next summer. Throughout the conversations, the Suns' stance had been consistently been the organization didn't believe Ayton was a max player -- a value assessment that's been met with surprise elsewhere in the league.

A significant part of Ayton's development and maturity has centered around the relationship and trust that he's built with coach Monty Williams in their two seasons together, and that'll be tested should Ayton spend the season believing he's headed to restricted free agency. Ayton blossomed under Williams, becoming the two-way force that the Suns imagined when selecting him No. 1 overall in the 2018 NBA Draft.

Ayton averaged 16.3 points, 10.3 rebounds and a block a game during the NBA season in 2020-2021. Among Ayton's playoff successes, according to ESPN's Stats & Information, he had the highest field goal percentage (66 percent) in NBA history in the postseason and shot 50 percent in 17 straight playoff games, trailing only Shaquille O'Neal (2006) for the longest in league history. Ayton held NBA Finals MVP Giannis Antetokounmpo to 53 percent shooting as the primary defender in Finals. Antetokounmpo shot 70 percent against the rest of the team.

Ayton and Paul's partnership was one of the most productive in the league a season ago, with Paul assisting on 143 Ayton baskets; only Golden State's Steph Curry and Draymond Green had more as a combination.