Manor Marussia team boss John Booth has praised the attitude and ability of Will Stevens and Roberto Merhi, as the 2015 season reaches its halfway point.
Stevens made his Grand Prix debut with Caterham at the end of 2014 before moving to Manor Marussia across the winter, while Merhi's Formula 1 experience was limited to selected practice outings with the now-defunct team last year.
Booth says that the pair have performed well in difficult circumstances, with Merhi registering the team's best 2015 result at the British Grand Prix courtesy of 12th position.
"We threw two rookies in with no pre-season testing and missing the first race altogether, and just to expect them to perform - which they have done - they’ve done an outstanding job," he told Formula 1.com.
"We’re over the moon with both drivers. Up until now we’ve given them a car that’s not been easy to drive and the engine must be at least 1-1.5 seconds slower than the best engine on the grid. We haven’t made their lives easy.
"They started getting very competitive a few races ago, but they seem to have had conversations themselves about how they want to conduct themselves on track.
"They’re both very intelligent guys, and they know each other very well of course. I think they’re developing into a strong team now."