Simon Harmer has bowled more balls than anyone else in the County Championship this season, and it's not even close. He's sent down 386.3 overs for Essex, 126.5 more than anyone else in the country. Only 15 men - Harmer included - managed more than that in the entire 14-match season in 2019 across both divisions, and he still has six four-day fixtures left to play this summer.

Unsurprisingly, he is exhausted. "The body is taking a beating," he laughs, speaking to ESPNcricinfo ahead of a must-win fixture against Nottinghamshire this week. "Most teams have had bye weeks, but our fixture list was nine games on the bounce, which has been pretty relentless. I pride myself on being able to do a job but I'm sure the body would appreciate a break from the workload."

No-one could accuse Harmer of failing to pull his weight. He has not been quite as devastating this summer as in previous seasons, with 34 wickets at an average of 26.41, but his hard graft in the holding role has allowed Essex to rotate their seamers in a four-man attack. Even still, he has managed two 10-wicket hauls, in wins against Durham and Derbyshire, and only three men have taken more wickets.

In fact, his performances in May were enough to earn him a nomination for the PCA's player of the month award through the Most Valuable Player (MVP) ranking system, which he has won after edging Craig Overton out in a public vote. He has been wicketless in his last two Championship appearances - the first time that has happened in his Essex career - but his match analysis of 12 for 202 against Derbyshire, useful runs from No. 8 and bucket hands in the slips were enough for him to be recognised.

"It's down to the public and their perception as to who they think deserves it," he says. "I guess it's a nice little achievement at the start of the season. [Against Derbyshire] the stars aligned - there was bad light on the first evening that they were batting so I had to bowl a lot of overs and then I just picked up where I left off in the morning. When it's your day, you need to cash in and go big because I knew the wicketless games were around the corner - and they were."

Essex are top of Group One - albeit Nottinghamshire and Warwickshire both have games in hand - and wins in their final two fixtures should see them qualify for the six-team Division One in September, but after titles in 2017 and 2019, plus a Bob Willis Trophy win last summer, they have not found things so easy this year, with two defeats and three draws in their first eight games. In particular, Harmer points to other teams becoming "smarter", preparing flatter home pitches that have stymied the effectiveness of their attack.

"I've found it quite difficult," he admits. "The wickets have been really flat, so I've just been trying to hold up an end. I love taking wickets but I know it's not always going to be like that, and at the back end of the summer when the wickets are dried and we're playing on used squares, I'll come into the game more. I just need to find ways to contribute where I can now: trying my best in the slips and fighting as hard as I can when I come in with the bat.

"Teams are getting smarter when we play away from home, because they know what they're going to get at Chelmsford. It has made life a bit tougher for us but we've kind of found ways when the chips have been down. I don't think we've had the start that we wanted to, but we've still found ways to win or draw when our backs have been up against the wall.

"I don't think it's a bad thing that we haven't got off to the greatest start: it's meant that the guys have had to really dig deep and work their nuts off to try and make sure we get the performances that we need. Where we are at the moment will bring the best out of the squad; in years gone by, when our backs are against the wall and we've got to find ways to win, that's when we've shown our true colours."

Harmer admits, too, that he has found things harder on the road than he is used to: he has 25 wickets at 20.20 at Chelmsford this summer, compared to nine at 43.66 elsewhere. "Teams are trying different formulas against us and against me. When you get onto a wicket and it's not really turning, there's only so much I can do, but when it's turning it's a completely different dynamic.

"If a batter is looking to either block or take you on, you always feel like you're in with a chance, but against spin, strike rotation is the biggest weapon that a batter has: if you're going at three or four an over and it's low-risk cricket for one, that's where you feel ineffective. There hasn't been anybody at Chelmsford who has played extremely well against spin; away from home, the hundred that [Rob] Yates scored at Edgbaston was a standout performance."

Harmer has long since given up on the ambitions he once held to play for England, and is now registered as one of Essex's overseas players alongside Peter Siddle after Kolpak deals were cancelled, meaning he is eligible for South Africa again. But he has been overlooked since he became available, with no contact from the board and no call-up to the squads, and appears to be at peace with the idea that he has played his final international.

"If that's the case, and that's the way my career pans out, I don't think there's a hell of a lot I can do about that," he says. "I tried to make the best of the situation I was in, and I've proved myself in terms of my performances in England and my worth to Essex.

"I haven't heard from Cricket South Africa since I signed my Kolpak deal in 2016 - there hasn't been any conversation. I don't know what the future holds. I've got to keep my head down and put in performances. The cream always rises to the top. If I'm good enough, I'll get selected; if not, I'll keep doing my thing."

As for other county spinners, Harmer thinks that the signs from this Championship season are positive for England. "There's some competition for spinners now. In the past few years, that might not have been the case - it was only ever really Jack Leach and Dom Bess, whereas now there's a lot more names flying around. That's only going to push someone like Leach to be better, with guys breathing down his neck.

"I've always thought highly of Amar Virdi: he gets a lot of revs on the ball and has the potential to be a really good spinner. I've watched Matt Parkinson bowl on streams but we haven't played against each other - hopefully if both our teams progress I'll get to see what he's all about. He does a great job for Lancashire. Jack Carson at Sussex too: I was really impressed when we played against them last year and he's been doing well for them this year."

But even with young bowlers coming through, what does it say that England have opted not to pick a frontline spinner in the Lord's Test at New Zealand this week? "It's a difficult place to bowl spin, and you'd back the English to know their own conditions. I'm pretty sure that The Nut [Leach] will play at Edgbaston but clearly they thought they didn't need one at Lord's. If [Mitchell] Santner does well and England haven't picked a spinner, there are going to be a few red faces."