does this make sense to do.....

I have the Canon 70-200 f/2.8L and the 400 f/5.6L (and I have owned the Canon 70-200 f/4L) and I shoot quite a lot of soccer. The first thing I would say is that the PERFECT soccer lens does NOT exist. Every lens currently offered compromises somewhere when it comes to shooting soccer.

If you get a good performing copy of the Sigma 120-300 and don't mind lugging and shooting with a lens that weighs over 6.5lbs, it comes as close as anything for an all-around soccer lens.

A 70-200 f/2.8L will cover 1/3 of the pitch closest to you very well and over half of it well enough. A 300 will cover 1/2 of the pitch very well, but still is lacking for covering the entire length of the pitch. If you like shooting from midfield on the touchline, this may be fine. I don't like shooting from there. I just don't get the composition I'm looking for with anywhere near the consistemcy that I do shooting from behind the goal line. YMMV, but I wish you good luck with that.

I just used the 400 f/5.6L for the first time this past weekend for shooting soccer and used it for a match that started in the late afternoon and ended after sunset (under the lights). The 400 f/5.6L performed surprisingly well in the late afternoon light and ever increasing ISO.

For the coming season, I will be using both the 400 and the 70-200 on separate bodies. I think a 70-200 and 400 combo is the best way to cover soccer, but it does require two lenses a second body is ideal, but not required.

If money is an issue, I would get the 70-200 f/2.8 and get the action that comes to me (chasing it mostly proves futile). You will get plenty of great action shots, just not EVERY action shot.

If money is not so tight, weight is not an issue and you really want/need a one lens solution, then the Sigma 120-300 f/2.8 could prove most useful.

If you really want the best (IMHO) soccer kit, I would get two 1DMkII bodies and a 70-200 f/2.8L IS and the 400 f/2.8L IS lenses with sturdy monopods for both.

JMHO,
Jeff

I agree with getting 300mm f4L IS + 1.4TC, better than Sigma 120-300 +1.4TC, still that canon is prime and has IS so if it is little bit close to 400 f5.6 its still with IS, so you can find a way to have long prime with IS and do great soccer shots.
By the way, 100-400 is starting from 4.5 i think in good light condition, i think primes better than zooms with TC's.

I shoot my daughter's soccer games with a 70-200mmL f/4. Its only teen age level soccer, but I find the range perfect. For pro soccer you'd probably need more reach though. For me that would mean the 100-400mmL. The 300mm is supposedly a great lens, but for action sports (where the subject can be close one minute and far the next), I prefer the adjustability of a zoom. The only problem I can see with the sigma 50-500mm is its slower speed and considerable weight.

Well he got the 120-300mm EX so we will have to see what he thinks about it when it arrives. I agree that a zoom is more flexible for framing on the fly, tho if you are happy to crop then the prime will often give better IQ. I wouldn't use the 300mm f4 IS. I had that lens and it is lovely in many respects but with a TCon the AF slows and it need light. Bigma, agree too dark ... great lens for wildlife but less for sports I reckon, tho' I'm sure many have it do a good job in that respect.