Boston Celtics star point guard Rajon Rondo may miss the start of the 2013-2014 NBA season, although the team is happy with the progress the franchise player is making with regards to the rehabilitation of his torn right ACL injury.

CSNNE.com is reporting that Rondo was in Boston recently and worked out with new head coach Brad Stevens. However, there is still no clear timetable as to when the floor leader will return for the 18-time NBA champions.

The four-time All-Star and only remnant of the team's 2008 championship squad tore his right ACL in Atlanta on January 25. Rondo had his knee surgically repaired on February 15. Celtics president of basketball operations Danny Ainge earlier expressed belief that Rondo would be back to lead the team for the start of the 2013-2014 season.

However, Stevens admitted that there is no schedule for Rondo's return. The new coach, however, said the Celtics leader is excited for the new season and situation that the team is in.

The Celtics have undergone a massive rebuilding program after trading away the face of the franchise, Paul Pierce, and former MVP Kevin Garnett to the Brooklyn Nets. This was after the Celtics fell to the New York Knicks in six games during the first round of the 2013 NBA Playoffs.

Aside from trading away their veterans, the Celtics surprised many observers when it tabbed Stevens, a former college coach, to lead the revamped line-up in lieu of former coach Doc Rivers. One of Stevens' earliest trips as Celtics coach was going to Louisville to meet up with Rondo sometime in July, as reported by ESPN Boston.