David Flatman: I hope Sale look after a valuable asset like Henry Thomas

From the Front Row: He will be under real pressure and that is tough on the body

I always worry a little when I see a prop forward burst on to the scene. For me, the most desirable introduction to first-class rugby for an aspiring bookend should be a slow, measured, silent one. Admittedly a somewhat unexciting approach, it has to be better for him. Propping is a brutal game and, while there will always be the odd spawny lump who sails through a long career unhurt, almost all find themselves on the surgeon's slab before long. An arrival conducted under the radar gives a youngster a chance to get to grips with the job at hand before heavy-hitting coaches and pros from around the league begin to analyse and deconstruct his technique.

I was one of those lads who appeared out of nowhere, and I quickly found myself on the test scene. After four years as a pro I felt invincible. I had played for England a few times, I was first choice every week at my club and I rarely struggled, even in the big games. Then, in year five, my shoulder went "pop". What followed was a decent career but one unquestionably hindered by a broken body.

In the end I had five shoulder operations, four on my Achilles tendon and one on my elbow for good measure. I am not weeping – I feel very lucky to have played for great clubs for so long – but I absolutely believe I played too often too young. I wasn't complaining at the time but over 100 first-class games in the five years following school proved too much.

This worry doesn't come around too often as good young props tend to sit behind more experienced, trusted men in their first few seasons. Harlequins' Kyle Sinkler is a very strong prospect on the tighthead, as is his squad mate Will Collier but, for now, they both spend most of their time developing their bodies for the seasons ahead and watching James Johnston do the job. Just as Dan Cole sat and watched Julian White and Martin Castrogiovanni for a time, those boys' time will come and, when it does, their bodies stand a better chance of lasting the required decade of hell.

When I watch Henry Thomas run out week after week for Sale I fear for his longevity. Playing for Sale is not like playing for Leicester. In a Tigers pack you are more likely to be moving forward. Sale – while their scrum is effective and, when Al Dickinson is playing, technically very proficient – just don't have the outright power of the top four teams. So he will be under real pressure and that is tough on the body.

One thing working in his favour is his athleticism; for a big lad, he can actually run. Almost all young props fall into one of two brackets: they can scrummage like a machine but barely catch, or they can play like a back-rower but struggle when it comes to repeated brute strength.

Thomas, in his first season at least, found the tight phases very tough. But the mark of the man is not how he takes his first big shot, but how he learns to take them from that moment, as they will keep on coming. Thomas's work on the tighthead has improved to a massive degree. This is testament to both his coaching and his aptitude for learning.

In Thomas I see all the ability of a Test tighthead. His level of involvement is enormous, his rugby intelligence is already miles ahead of most props and his heft and sheer power are growing. He is a talented young man but he needs more than that; he must be durable. I think another year or two of watching as much as he plays would do him real favours. I only hope Sale afford him that luxury.