The four rookies who must undertake the IZOD IndyCar Series' Rookie Orientation Program before being eligible to participate in this year's Indianapolis 500 will have to wait until the weekend of May 11/12 to complete their mandatory testing.

ROP was originally scheduled to take place at the two-and-a-half mile Indianapolis Motor Speedway on April 11, but the session was cancelled because of weather forecasts suggesting that little if any track time would be possible.

With the Long Beach event taking place this weekend and then teams having to prepare for the flyaway race to Brazil to be held on May 5 there is little available time to reschedule ROP ahead of the official start to the three week long Indy 500 programme of events which gets underway with 'Opening Day' on May 11.

As a result, series officials confirmed this week that ROP will be held in the middle of the afternoon on both the Saturday and the Sunday of that first weekend. The track will be cleared between 2pm and 4pm to allow Tristan Vautier (Schmidt-Peterson Motorsport), AJ Allmendinger (Penske), Carlos Munoz (Andretti Autosport) and Conor Daly (AJ Foyt Racing) to complete their mandatory test runs.

The rest of the day from noon till 6pm will see the track open to all cars for general practice.

"With some teams having to load equipment for Brazil following the Long Beach event next week, and long-standing community activities scheduled at Indianapolis Motor Speedway prior to Opening Day, moving ROP to Opening Weekend was the only option we had to give the ROP participants adequate track time and a chance to complete the program," explained Brian Barnhart, IndyCar's president of operations and strategy.

Rookie orientation is a formal procedure by which any drivers without recent experience of racing on the two-and-a-half mile Indianapolis Motor Speedway in current IndyCar-specification equipment need to demonstrate that they are able to run safely at speeds of over 200mph.

ROP is a three-step process, with the candidate having to run a consistent line within a defined speed range for a set number of laps. The first stage requires ten laps between 200 and 205mph, while the second requires another ten laps this time between 205 and 209mph.

Rookies must complete these first two steps during the two special ROP time slots or else they will not be able to participate in any of the rest of 2013's track activities, and will not be able to attempt to qualify for the race. However, the third and final stage of ROP - 15 laps at speeds over 210mph - can be completed at any time during the rest of the week ahead of qualifying, while more experienced drivers are also on track.

IndyCar said this week that officials will work with any driver unable to participate in ROP during the opening weekend to schedule a time to complete the three phases of ROP prior to qualifying.

The process should present little difficulty for Munoz and Vautier, both of whom competed at IMS last year in the Firestone Indy Lights Freedom 100 support race. They finished in second and third place respectively behind 2012 race winner Esteban Guerrieri.

It's another matter for AJ Allmendinger, who has only ever raced here in a NASCAR stock car in the Brickyard 400; and for Conor Daly, who has been competing in the distinctly non-oval GP3 Series in Europe.