Fabio Leimer says he was signed to his current role at Manor with the belief the team would try to give him a race seat towards the end of the 2015 season.
Leimer was signed as Manor's reserve driver in June and is currently only confirmed to be taking part in select FP1 sessions this season. While Will Stevens has a deal until the end of the season Roberto Merhi does not have a contract which covers the full 2015 season, though team boss Graeme Lowdon recently said the Spaniard is not under pressure after Leimer's arrival.
However the 2013 GP2 champion thinks there is a strong chance of a Manor race seat this year.
"We were in contact with Marussia since 2013 but in the end we never had the budget. It was all over for me, Formula One, it was over," Leimer told ESPN.
"Then I got a call saying 'we are interested to have you as a third driver and maybe even for some races, maybe at the end of the season'. So we were 'yeah, sure, we will do it' and I'm very happy and it's helping me a lot."
Asked to clarify if that meant he was hoping to drive in a grand prix this year, he replied: "Yes."
The Swiss driver also expects to make his Manor debut in free practice at the British Grand Prix.
"At the moment it is looking like Silverstone will be my first practice session. As you know Formula One is changing quite quickly - if someone comes and is paying a lot of money it is changing again. But at the moment it looks like Silverstone and maybe a chance at the end of the season to do some races."
Leimer also suggested Manor has ditched plans to introduce a new car during 2015, with the team still using a 2014-spec chassis and Ferrari engine.
"At the moment it looks like they will stay with the car like that, because it makes no sense with the car like that. It makes no sense now with a new car so they are really working for the next year and pushing forward or next year."