Phil Mickelson has been given the green light by officials to play in this week's Byron Nelson Championship, despite missing Wednesday's pro-am tournament.

Champion here in 1996, Mickelson was left stranded in Arkansas on Tuesday night after severe thunderstorms in the Dallas area forced the cancellation of his scheduled flight.

"Phil did everything physically possible to get here Tuesday night but was grounded in Little Rock due to circumstances completely beyond his control," PGA Tour chief of operations Henry Hughes said in a statement.

Under Tour regulations, players are required to take part in pro-ams if they wish to compete in the tournament proper.

However, the Tour can make exceptions if there are "extenuating circumstances".

World number four Mickelson, the highest-ranked player in this week's field, had travelled to Little Rock to take part in a charity event on Tuesday.

After missing his early morning teeoff in Wednesday's pro-am, he eventually arrived at the TPC Four Seasons Resort Las Colinas in time to have lunch with his amateur partners.

The three-times major winner will be making his first tournament appearance since announcing on Monday he was switching allegiance to swing coach Butch Harmon.

Left-hander Mickelson has not played competitively since his title defence at the Masters just under three weeks ago when he tied for 24th.

The Byron Nelson Championship starts on Thursday.