Chris Thompson realized right away that Derrius Guice was upset. The Washington Redskins’ running backs huddled on the sideline Sunday in Green Bay, Wis., after a hit to Guice’s left knee knocked him out of the game during the second quarter of a 20-15 loss to the Packers.

He appeared to be walking fine, and he flashed a thumbs-up to signal that he was okay. But Thompson knew better.

“He was down,” Thompson said. “He wasn’t feeling too great, wasn’t saying much. Just kind of like, ‘Man, why has this happened to me again?’ ”

In another injury blow to his young career, Guice will not play this week against the Philadelphia Eagles, Redskins interim coach Bill Callahan said Monday afternoon. Guice had an MRI exam earlier in the day to determine the extent of the injury; when Callahan met with reporters, he said the team’s director of sports medicine, Robin West, had not yet seen the results.

Some players and Redskins staffers said they believe this isn’t as serious as his previous injuries as a pro — a torn ACL in his left knee that forced him to miss all of last season and a torn meniscus in his right knee that sidelined him for nine games this year. But at a minimum, Guice will miss Sunday’s game, and Callahan said the Redskins haven’t ruled out shutting him down for the final two games of the season, too, no matter the severity of the injury.

This consideration is understandable, given the team being eliminated from the postseason with a 3-10 record and the 22-year-old’s injury history. Guice has played in five regular season games since the Redskins selected him in the second round of the 2018 draft, and he left two of them early with a knee injury.

The Redskins are likely to replace Guice with a combination of Wendell Smallwood and Thompson as complements to starter Adrian Peterson.

Guice, who did not speak with reporters Monday or after Sunday’s game, was making progress before his latest setback. He had easily the best game of his short career in a Dec. 1 win against the Carolina Panthers, registering 129 yards on 10 carries and the first two rushing touchdowns of his career. He finally looked like the explosive power back who, at LSU, became the first player in SEC history with three career games of 250-plus rushing yards.

In one of several tweets Guice sent Monday, he referenced his stat line since returning, including a 7.1 yards-per-carry average. “I was getting in rhythm,” he wrote.

“It’s sad — we’re all sad about it,” Thompson said. He added that injuries are a part of football but that he felt for Guice because “mentally, it’s just tough.”

“Weird” is how Callahan described the injury. In the middle of the second quarter, Guice burst through the right side for a 23-yard gain, and Packers safety Darnell Savage lowered his shoulder into Guice’s left leg. Callahan said Guice’s leg “got caught” on the turf at Lambeau Field, which was “slick” from freezing and thawing leading up to the game. The Redskins practiced for those field conditions, but multiple players still slipped Sunday.

“Those are freakish things,” Callahan said. “I don’t think [you can attribute it to] necessarily running style, per se.”

If Thompson thought the situation deflated Guice on Sunday, the second-year running back apparently rebounded by the time he met with Callahan for “a long time” Monday morning. Callahan praised Guice’s relentless positivity, and he credited him for giving the Redskins “a catalyst that most teams don’t have.”

“He’s got more energy than the entire building, so this ain’t going to hamper him or stifle him or hold him back by any means,” Callahan said. “I love the guy. I’m proud to have him on our team, and I’m proud to coach him.”

Thompson noted that knee injuries, while significant for all players, can be especially difficult for a powerful back such as Guice, who at 5-foot-11 and 225 pounds makes sudden cuts and powers through would-be tacklers. Thompson tore the ACL in his left knee as a senior at Florida State, and he remembered the effects of the injury lingered far beyond physical pain.

Thompson credited Guice for playing so well against Carolina because, when most players come back from ACL surgery, they tend to compensate and favor their other knee, but Guice couldn’t because he had just torn the meniscus in his right knee.

“Mentally, when you have injuries to both knees, it sometimes can make you nervous,” Thompson said. “It makes you play different because you start to worry.”

What Guice needs now, Thompson said, is rest, given that Guice has essentially been rehabbing injuries nonstop since the torn ACL in August 2018. He might get that rest in the season’s final three games. He is a player the Redskins have high hopes for, and perhaps additional rest will allow him to get back to full strength.

Thompson said he told Guice on the field Sunday to keep his head up, and that when the time came to get back to work, he could put himself back together again. It was a message similar to one Guice tweeted Monday: “There’s always light at the end of the tunnel!!!” he wrote, adding a pair of smiley faces as punctuation.

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