Rose praised Simpson's performance on the greens this afternoon, but believes that Europe are still in with a shout if they can win the session 3-1.
"Webb Simpson played really, really well," Rose told BBC Sport. "He putted brilliantly this afternoon after he clicked into gear. Credit where credit is due.
"Right now it's slipping away but it's not over for sure. Right now, looking at the scoreboard is bleak. But if we get some momentum underway it could silence this place. To ignite things we'll need a 3-1 session this afternoon."