McGruder, 30, is 6-foot-4 and appeared in just 16 games last season, averaging 5.7 points and 1.4 rebounds.
Detroit waived him last week to avoid guaranteeing his $5 million salary for 2021-22. As Cohen noted, odds are, his new deal is therefore for likely less than that amount and is not guaranteed.
Joseph, 29, is 6-foot-3 and was also waived by the Pistons on Friday. He came to Detroit via a late-season trade with the Kings, showing some veteran leadership on an otherwise rebuilding club.
Joseph averaged 6.6 points and 2.5 assists in 44 games with the Kings, then increased those averages to 12.0 points and 5.5 assists in 19 appearances with the Pistons. Of those 19 games, Joseph started 11.