McLaren sources at Silverstone say that the plan to run a team in IndyCar has been shelved indefinitely because the team owners have decided that they must concentrate on returning to contention in Formula 1.

The team began the season looking strong, with two double-points finishes for Fernando Alonso and Stoffel Vandoorne in Australia and Bahrain, but recently has found itself slipping backwards in the F1 pecking order. Vandoorne has not scored in six races and Alonso has been unable to do better than an eighth-place finish during that same stretch.

This is below the team’s expectations and has led to the departure of the team’s racing director, Eric Boullier, and a restructuring of the F1 operations. Part of the logic behind the McLaren-to-IndyCar idea was to cross-sell sponsorships between F1 and IndyCar, with the same livery appearing in both series. Now, however, splitting the effort is not deemed to be sensible, and F1 is the company’s core business.

The idea may resurface in the future, but only when things are going better in F1.

IndyCar team owner Michael Andretti, who worked with McLaren to field Alonso’s 2017 Indy 500 effort, said on his visit to F1 in Canada on the June 9-10 weekend that if there was to be a McLaren IndyCar team in 2019, a decision would be required almost immediately, in order to have things properly structured. That was more than a month ago.

There is still a possibility that Alonso might run in the Indy 500, although this is likely to clash with Monaco, as usual.

There is the additional problem of the Alonso now being a Toyota factory driver in the FIA World Endurance Championship, which would make it problematic (but, apparently not impossible) for him to race with Honda engines at Indianapolis.

Honda and Toyota are celebrated rivals, but Honda motorsport boss Masashi Yamamoto said at the French Grand Prix three weeks ago that he was only an advisor and that the decision would be made by American Honda. Toyota, on the other hand, is unlikely to want to see its star driver winning for Honda in the United States.

Meanwhile, as far as IndyCar CEO Mark Miles is concerned, McLaren is still a possibility to join the IndyCar Series in 2019. He told Autoweek on Sunday in Toronto that he had nothing more to report from a week earlier, when he told Autoweek that McLaren CEO Zak Brown had said rumors McLaren would not join IndyCar were “crap.”

McLaren has been quiet in the past few weeks regarding interest in IndyCar, but that should be expected after it has focused on getting its Formula 1 team more competitive. Two-time CART champion and 2003 Indianapolis 500 winner Gil de Ferran replaced Boullier as McLaren sporting director on July 4.

Since that time, there has been little talk about McLaren joining IndyCar, but Miles said that doesn’t mean they have reached a decision that it won’t happen.

“No. Period.” Miles told Autoweek Sunday morning in Toronto. “I think Zak will be straightforward with us and keep us informed and when he has news one way or another we’ll know it.”