Schaffer, a Cincinnati native who played at La Salle High School and the University of Cincinnati, has suffered two concussions this preseason. He signed with the Bengals' practice squad for the final eight games of the 2012 season and played nine games last season.
Westbrooks was a seventh-round pick of the Bengals this year out of Georgia Southern. He has a thumb injury.
Collins played at Division III powerhouse Mount Union and had three catches for 33 yards this preseason.
The Bengals made five moves on Monday. They terminated the contract of cornerback R.J. Sanford, releasing him to free agency. They also waived kicker Quinn Sharp, wide receiver Ryan Whalen, defensive tackle Larry Black and rookie safety Isaiah Lewis.
Whalen had played in 17 games for the Bengals over the last three seasons since being drafted out of Stanford in the sixth round in 2011. He had 11 catches for 80 yards on offense while playing mostly on special teams.
Sharp made field goals of 34 and 51 yards in the fourth quarter of Sunday night's 19-13 win at Arizona that provided the winning margin. This was Sharp's second year of kicking with Bengals in camp.
"These are always tough conversations," said Lewis. "We've been pretty forthright with the players that we bring in here that we'll give them an opportunity to play, even if they're the undrafted college free agent types, that we get them out there, we get them on tape so we give them an opportunity. Look at what Quinn Sharp did. (Special teams coordinator) Darrin (Simmons) comes in pleading with me twice last week to let Quinn get some kicks in and he responded. You've got to feel good about that."
The Bengals wrap up their preseason schedule on Thursday against Indianapolis at Paul Brown Stadium. NFL teams must cut their rosters to 53 active players by Saturday at 4 p.m. so Thursday's game will be the final shot for players on the bubble to audition for jobs on the active roster or the practice squad.
Lewis was non-committal Tuesday when the question of how much, if at all, his starters would play against the Colts.
"They all expect to play," said Lewis. "We'd like to expect them all to play."