ALLEN PARK — Ndamukong Suh has not participated in the Lions voluntary offseason workout program which started on Monday. Reggie Bush was asked about Suh’s absence on Thursday morning.

“From what I know it’s a contract thing, so that’s the business side of stuff,’’ Bush said. “We all go through it, everybody understands no one’s looking down on him.’’

Suh, who is signed through 2014, is working on a contract extension.

Bush said he’s not certain that’s the reason Suh is not in attendance because he hasn’t talked to him.

A year ago, Matthew Stafford was working on an extension and had full attendance during the offseason program.

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