Although Raikkonen is a leading contender for Mark Webber's Red Bull seat next year, any vacancy at Lotus is likely to be hotly sought-after by experienced F1 drivers given the team's competitiveness.
Lotus gave slight consideration to replacing Grosjean with GP2 champion Valsecchi had the Frenchman's erratic Monaco Grand Prix form become a trend, but Grosjean has since steadied his season and returned to the podium in Germany earlier this month.
After his day of running with Lotus in the Silverstone young driver test on Thursday, Valsecchi acknowledged it would be hard to find a way into the Lotus race line-up.
"Formula 1 is so tough and it's so difficult to be involved. There are so many great drivers in it," he said.
"We have Kimi Raikkonen - one of the best in the world, maybe the best at the moment.
"We have Grosjean, he just came from a fantastic result and a fantastic race at the Nurburgring.
"So it will probably not be easy for me. But I will do my maximum at the end of this season and we'll see.
"I need a little bit of luck, to be good and to deserve it."
Valsecchi thinks it is tougher to demonstrate his F1 potential in the reserve role than it was when racing in GP2 last year.
"You have to try the see the situation from an outside point of view and be 100 per cent objective," he said.
"But it's also not easy to understand if I really deserve it 100 per cent - how can I tell you that?
"In my mind, I deserved it at the end of last season when I was champion in GP2, when I was conserving the tyres really well and I was really a leader in my mind at that time."