In the wake of what he admitted was a disappointing outing in Turkey, David Coulthard and Johnny Herbert believe it is time for Michael Schumacher to reconsider his future to F1.

In the eyes of many, the seven-time champion's decision to return to the sport, albeit with a new team, was a lose/lose situation. Damned if he beat the new breed of drivers, damned if he didn't.

In the short time that he was away from the sport - three seasons - it has moved on, and his age, the new technology, new rules and the abundance of raw talent has clearly caught him by surprise.

While fans were willing to give him the benefit of the doubt last season, this year they find themselves frustrated. Rather than mixing it with the likes of Vettel, Hamilton and Rosberg, he is finding himself defending (and losing to) the likes of Kobayashi, Alguersuari and Petrov.

Speaking after Sunday's race, the German admitted to the BBC that "The big joy is not there right now.", going on to take full responsibility for the first lap clash with Petrov which effectively ruined both their races.

Coulthard, who enjoyed on and off-track, clashes with Schumacher, believes the German needs to think long and hard about his future, acknowledging that the seven-time champ is no longer enjoying himself.

"It is for Michael to decide when he wants to retire," the Scot writes in the Daily Telegraph. "His record of seven world titles and 91 race wins has earned him that right.

"We had our differences on and off the track but I have always respected Michael as a driver," he continues. "If he wants to see out his contract at Mercedes and stay until the end of next season then he should. If he feels he can still be competitive, and he is still enjoying himself, then fair play to him. The trouble is at the moment he is not enjoying himself and he does not look consistently competitive.

"I found his drive on Sunday awkward to watch at times," admits the driver turned commentator. "The collision with Petrov, which left him fighting a rearguard action for the rest of the race, was by his own admission his fault. He spent the rest of the race in skirmishes with mid-ranking cars; often the attacked rather than the attacker. It is an unfamiliar position for him which maybe explains why he looked like a fish out of water.

"He said at the start of the year that he had no excuses," the Scot continues, "he asked to be judged on his performances in his second season. After four races, it is not looking great."

Meanwhile, Johnny Herbert, who partnered Schumacher at Benetton in 1995, believes that the German's poor form isn't about age but that the current opposition is better.

"He did not return just to run in the middle order," writes Herbert in Abu Dhabi's The Nation newspaper. "His dream was to win again and make Mercedes race winners, but it has not turned out that way and I would be surprised if he chose to continue.

"The simple fact is that he is no longer the best driver on the track," the Essex born racer continues. "Schumacher has not lost any of his skill, the new generation of young drivers are just better than him. It is a case that the level required to win in F1 has gone up and he is not at that standard anymore."

The youngsters who watched idolised Schumacher as they came up through the motorsport ranks, now find themselves on track with the German legend. But they are no longer in awe of him, now he is just another rival, another driver to be beaten.

"In the past, Schumacher was able to be very forceful in races and his sheer presence would almost force cars to pull aside or back out of situations," writes Herbert. "But this is no longer happening and you are seeing this with the number of incidents he has been involved in both this year and last season as well."