Vitantonio Liuzzi’s full-time return to Formula 1 has not gone well so far this year.

He’s been off the pace of team mate Adrian Sutil in qualifying and the races.

Will Force India persist with Liuzzi until the end of the season – or will they draft reserve driver Paul di Resta in before the year is out?

Sunday’s race was the latest in a string of poor results for Liuzzi. He says he is struggling to get to grips with the 2010 tyres:

Basically we had the same problem as Barcelona ?����ǣ there?������s a lack of grip overall. We cannot put load on the rear tyres. I struggle as if the tyres were cold. We were a bit more optimistic after Monaco because even if the problem had not been solved completely, we found a way to go around the issue. But Istanbul is a proper track with a lot of high speed, medium speed and low speed, so you need to find a compromise. And in fact we were struggling like in Barcelona.

Vitantonio Liuzzi

He is 6-1 down against Sutil in qualifying and without Vitaly Petrov’s crash in Monaco the score would probably read 7-0. But it’s the scale of Sutil’s advantage that will be most worrying Liuzzi:

Race Liuzzi’s gap to Sutil* Bahrain +0.657 Australia +0.697 Malaysia +1.34 (wet) China +0.49 Spain +0.869 Monaco -0.257 Turkey +1.007

His average deficit to his team mate in dry qualifying is over half a second – more than any other driver bar Vitaly Petrov and Lucas di Grassi, who are both rookies with experienced team mates.

His race pace has been off by a similar amount – have a look at his form here.

This kind of gap might be acceptable if Liuzzi was a rookie or if he was up against a driver of Lewis Hamilton or Fernando Alonso’s calibre. But Monaco was his 50th Grand Prix and, with all due respect to Sutil, he is not thought of as one of F1’s elite.

Force India are a team on the fringes of the top ten and Liuzzi’s shortfall in performance to Sutil is keeping them from having both cars in the points regularly.

The team may consider that, if they’re going to have one driver that far behind the other, it might as well be a rookie who they could expect to make a faster rate of progress.

The team has Paul di Resta waiting in the wings and have already put the Mercedes-backed DTM driver in the car in several Friday practice sessions this year.

Is Liuzzi’s second crack at Formula 1 about to come to an end? Should Force India give him longer to prove he can get up to speed – or take a gamble on di Resta? Have your say in the comments.

Read more: Vitantonio Liuzzi 2010 form guide

*For each qualifying session the drivers?������ lap times were compared in the final phase of qualifying where both cars competed.