The diagram below is taken from James Vigus' Play the Slav, Everyman, 2008, page 177. The position depicted arises after the following sequence:
1.d4 d5 2.c4 c6 3.Nc3 dxc4 4.e4 b5 5.a4 b4 6.Nb1 Ba6 7.Nf3 Nf6 8.e5 Nd5 9.Ng5 h6.
The untried 10.Ne4, focusing on the d6-square, is perhaps not so bad for White: for example, 10...e6 11.Nbd2 c3 12.Nc4 Bxc4 13.Bxc4 cxb2 14.Bxb2 Be7, when the potentially strong bishop on c4 gives him arguable compensation for the pawn.
Untried? Sort of.
But sort of not. Let's have a look, for instance, at page 119 of James Vigus' book Play the Slav (Everyman, 2008) in which the following sequence is investigated:
1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dxc4 5.e4 b5 6.e5 Nd5 7.a4 e6 8.Ng5 h6 9.Ne4 b4 10.Nb1 Ba6
bringing us to the following diagram...
...which is the same position as would have arisen after the "untried" 10.Ne4 and then 10...e6 as given above.
Three game references are given.
[Number one in an occasional series]