Center Jarrett Allen hurt his right hand at some point in the first half of Cleveland’s 142-105 rout of the New York Knicks on Friday night, an injury that could leave the NBA’s top team without one of its key players. Allen is expected to undergo an MRI on Saturday, an off day for the team. The Cavs, who improved to a league-best 46-10 with their most-lopsided win ever over New York, host the Memphis Grizzlies on Sunday. Allen played just a few minutes in the second half before the Cavs announced he would not return. “X-rays were negative, so that’s good,” coach Kenny Atkinson said. “I do think he’s going to get an MRI tomorrow. He came up to me during the game. He goes, ‘It’s really bothering me. I’m not going to be able to finish.’ But good X-rays were negative.”