Two football players are running towards each other on a collision course. Player 1 has a mass of 75 kg and a speed of 6 m/s. Player 2 has a mass of 100 kg and a speed of 8 m/s. What is their combined

Mass of the first player, $m_1 = 75 \text{ kg}$.
Speed of the first player, $v_1 = 6 \text{ m/s}$.
Mass of the second player, $m_2 = 100 \text{ kg}$.
Speed of the second player, $v_2 = 8 \text{ m/s}$.

Since the players sprint straight at each other, their initial velocities are in opposite directions. Let's assign the direction of the first player as positive and the second player as negative.
Initial velocity of player 1: $u_1 = 6 \text{ m/s}$.
Initial velocity of player 2: $u_2 = -8 \text{ m/s}$.

In an inelastic collision where the two objects stick together, the total momentum before the collision is equal to the total momentum after the collision.
The formula for conservation of momentum in an inelastic collision is:

where $v_f$ is the combined speed of the two players after contact.

The negative sign indicates that the combined players move in the direction of the second player's initial motion. The question asks for the combined speed, which is the magnitude of the velocity.
Speed $= |v_f| = |-2 \text{ m/s}| = 2 \text{ m/s}$.

The combined speed of the two players instantly after contact is $\boxed{\text{2 m/s}}$.