Lions running back J.D. McKissic knows the NFL doesn’t wait for anyone. And faced with the uncertain prospect of Kerryon Johnson’s return from the knee injury he suffered in Sunday’s 42-30 loss to the Minnesota Vikings, McKissic stated the simple fact facing the Lions’ run game. “Kerryon’s a great player,” McKissic said Sunday night, “but we can’t wait for him to come back.” That means if Johnson isn't ready for Sunday’s game against the visiting New York Giants — ESPN's Adam Schefter tweeted Monday night Johnson is expected to miss "some time" with a knee injury and is week to week — the bulk of the workload would fall to Ty Johnson and McKissic, as it did against the Vikings after Kerryon Johnson exited. Ty Johnson became the lead back. He played 49 snaps, or 64% of the offensive plays, on Sunday and had 10 carries for 29 yards. McKissic played 19 snaps and had five carries for 29 yards. “We’re always ready with Ty and J.D. McKissic,” coach Matt Patricia said Sunday. “Those guys work really hard in practice.” The question is whether Ty Johnson and McKissic would be able to step into Kerryon Johnson’s role as a traditional between-the-tackles runner. “It just means when our number’s called you’ve got to know what you’re doing,” Ty Johnson said, “go in and make sure the offense doesn’t miss a beat.” McKissic said the running back group was ready and able to fill whatever roles the team needs. “I’m very confident,” McKissic said. “I think we’ll do good. It’s all about preparation. We’ve got to play next Sunday, so we have plenty of time to get it a game plan down and practice on what we’ve got to do best. “We’ve got Tra Carson as well. But it’s just a matter of time. Just stay focused and prepare.” A week of preparation might make a big difference. Ty Johnson said the Vikings’ defense did a good job adjusting to the Lions’ offense and getting to the ball quicker when they saw the Lions using an extra player for chip blocks. The Lions accrued 65 of their 81 rushing yards in the first half and only ran the ball five times in the second half. Now it’s on to the Giants, who had the 26th-ranked run defense after Sunday, allowing an average of 131.4 yards per game. And the Lions’ running backs, with or without Kerryon Johnson, say they’re ready. “It’s something you’ve got to be ready for in the NFL,” McKissic said of dealing with injuries to teammates. “You know you’re number’s going to be called — you don’t know how but eventually it will be called. So you’ve just got to be ready with all the preparation that you went through. It’s time to bring it out onto the field.” Contact Carlos Monarrez at cmonarrez@freepress.com or follow him on Twitter @cmonarrez.