Returning Button hit with 15-place penalty for engine change

MONACO - Jenson Button's one-off return to Formula One at the Monaco Grand Prix is proving problematic.

The veteran British driver is likely to start Sunday's race from the back of the grid after his struggling McLaren team was forced to make an unscheduled change to the car's power unit and incurred a 15-place grid penalty.

Given that McLaren has been way off the pace in qualifying, the 37-year-old Button is highly likely to be starting last among the 20 drivers after qualifying later Saturday.

"It's awful for Jenson and awful for McLaren and not expected at all," McLaren racing director Eric Boullier said. "But it's Monaco, so we'll try anything we can."

It is set to be another frustrating race for McLaren, which is struggling with Honda engines as it did throughout most of last year.

Teammate Stoffel Vandoorne has already been penalized three places in Monaco, for causing a collision with Williams driver Felipe Massa two weeks ago at the Spanish GP.

Fernando Alonso may have picked the perfect weekend to be away.

The two-time F1 champion has been given permission to skip Monaco so he can race at the Indianapolis 500 on Sunday.

Button, who retired from F1 last year, was drafted in to replace Alonso just for this race.

McLaren is the only team not to score a point after five races this season.