Manor have eased fears that the arrival of Fabio Leimer could signal the end of Roberto Merhi's racing days with the team.
The Dinnington-based squad confirmed the signing of 2013 GP2 champion Leimer ahead of the Canadian Grand Prix, leading to speculation that Merhi could be on his way out.
Merhi joined Manor at the start of the 2015 campaign with the team initially stating that he had been contracted for the "opening few races", but seven races later he is still with the team.
Asked by F1i.com if Merhi was under pressure due to Leimer's arrival, sporting director Graeme Lowdon said: "No, not at all. We’d been running without a reserve driver and although we have various arrangements in place to cover that situation, it’s better to have that sort of area covered with someone who’s with the team all the time.
"These cars are so complex now, it’s not a case of just strapping someone in. So there are huge advantages to having a third driver and yes, you’re quite right, it keeps everyone honest and there’s no harm in that.
"These guys all know each other and feed off each other and the other thing is that with the way regulations are going it’s harder to find the right drivers with the right experience."