Manor has signed 2013 GP2 champion Fabio Leimer as its reserve driver for remainder of 2015 F1 season.
The 26-year-old Swiss, a winner of the 2011 GP2 Final, is also a former Formula Master champion, prior to which he competed in Formula Renault 2.0 and Formula BMW ADAC.
Leimer will join the team at selected races, working with the drivers and engineers to aid the team's development programme and on standby to deputise for a race driver in the event that they are unable to take part in race weekend activities.
To prepare him for the role, the team will be providing him with the opportunity to drive the MR03B in selected FP1 sessions over the coming months.
"I'm thrilled to be provided with this opportunity," said Leimer, "and I'd like to thank the Manor Marussia F1 Team for the faith they have shown in my ability. In particular I'm very excited to have the chance to drive the car in selected FP1s, but I am also looking forward to spending a lot of time trackside with the team, contributing my observations and experience in engineering situations and also learning about the team and a Formula 1 operation. It's a huge step for me and I can't wait to get started and hopefully reward the team's confidence in me."
"We're delighted to welcome Fabio to our team," added John Booth. "We always keep a close eye on drivers competing in the feeder series and their potential for making the step up to Formula 1. Fabio has been on that radar for a number of years, so we're pleased to give him the opportunity to progress as he is a very talented driver and certainly deserving of this opportunity.
"Fabio will be joining us at selected races for the rest of the season, contributing to engineering meetings and on hand to substitute for either race driver should they be unable to compete at any stage. Familiarity with the car is therefore important, so we plan to run Fabio in a number of opening free practice sessions this season, allowing us to further evaluate his potential."
The recruitment of Leimer, follows a number of impressive technical signings by the team, including former Mercedes technical director Bob Bell.