What am I missing?

So Martin is killing the Redskins defense running wild all over them and then I noticed that Sims was in the game for a long period of time. Why in the hell was Martin out for that long? Both in the first and second half. This dude is always getting tackled by his shoe strings and can never make anyone miss in the phone booth ... What the hell am I missing here. Doug should be the Arab in the RZ and basically even on third downs... Sims should spell Martin only when his tired.. I was very disappointed in yesterday's lost and the sad part is that I've come accustomed to the defense playing so bad...Lovie needs to go today and see what Koetter can do.