Alastair Cook must now concentrate on captaincy - Agnew

Gary Ballance and Alastair Cook put England into a strong position by adding 158 for the second wicket

I can only imagine what Alastair Cook has been going through during his and England's wretched run of form.

Thanks to his personal trough of only 638 runs in 27 innings since he made a century against New Zealand at Headingley in May 2013 and his team's 10-match winless streak, people have been queuing up to criticise the England captain.

His 95 on the first day of the third Test against India at Southampton, a day which England closed on 247-2, means he now has every right to stick a couple of fingers up at some of those people. He won't, because he's far too nice a bloke to do that.

Even through all his troubles, Cook, 29, has retained support from a large section of England fans. Everyone in Southampton was willing him to get a hundred and even the ovation he got when going to lunch on 48 was quite amazing.

But, though a century would have been perfect, sometimes these things are not meant to be. And, yes, the wait for that three-figure score goes on, but he can still take a huge amount away from this innings.

Cook was dropped on 15 by Ravindra Jadeja at third slip, so he needed some luck, but even that can be a sign that things have turned for you.

He played in an uncomplicated manner and looked as though he was enjoying it. After winning the toss and batting first in conditions where he could have justifiably taken the easy option of bowling, he accumulated nicely against an India attack that was not quite up to the standard of the previous two Tests.

Cook's innings was not only a contribution for himself, but also for the other senior players in the England side who have been underperforming. Maybe now the likes of Ian Bell, James Anderson and Stuart Broad will put in the sort of display that Cook has.

After all, it is the younger players who have been impressing for England recently, none more so than Gary Ballance.

A record of three hundreds in his first six Tests is extraordinary and puts him in a list that only includes Len Hutton, Les Ames, Ravi Bopara and Jack Russell (not the wicketkeeper, the batsman of the 1920s).

Some people doubted the Yorkshire batsman's ability to fill the number three spot, but he's becoming like a left-handed Jonathan Trott. Cook will take the headlines, but it was Ballance who became the cornerstone.

Now, England have got to make sure they take full advantage of their first day's work. Batting collapse after batting collapse has ruined good, strong positions and this time they have to nail it down.

You hope that through Cook turning it around, the team will turn with him and get back to playing more disciplined, careful and successful cricket.

Until that happens, Cook will still have his detractors because, they will say, we always knew he could bat.

The question is, will this translate in to a more confident, effective and decisive style of captaincy? That is what people want to see.

Now he has got runs, he won't have the likes of me asking him about his form. He must continue to bat well but concentrate on the captaincy because only when England again produce results will his critics be silenced.

For now, though, those who know Cook, how hard he works and how determined he is to make this work will be very pleased for him.

Jonathan Agnew was talking to BBC Sport's Stephan Shemilt

Listen to Geoffrey Boycott and Jonathan Agnew review the first day on the Test Match Special podcast