Di Resta admits the situation affects his preparations for the new season.
Jan.13 (GMM) Paul di Resta has admitted he is surprised Force India is taking so long to decide his 2013 teammate.
Already openly disappointed to have missed out on a move to a bigger team, 26-year-old Scot di Resta is yet to learn who will be replacing his 2012 teammate Nico Hulkenberg, who has switched to Sauber.
Asked if he is surprised about the delay, he told Press Association: "I am surprised there has been nothing yet.
Asked if the situation affects his preparations for the new season, di Resta insisted: "Ultimately, it does.
"But at the end of the day, I know my job, and I am fully focused on what I need to achieve at the moment.
"I know who my team are, who my mechanics are. I'm feeling quite good about it, very positive. I've been at the factory and the vibe is very high."
Di Resta, who admits he was disappointed with his second half of last season, scored 17 fewer points than German Hulkenberg in 2012.
"I've been through times like that where you just need to dig deep, and eventually you get out of it. Hopefully this year will be the year," he said.