Rams tweak roster and wait for holdout Aaron Donald

The Rams on Monday begin preparations for their season opener against the Indianapolis Colts.

Finalizing the players that will actually be on the Rams roster, however, remains a work in progress.

A day after NFL rosters were trimmed from 90 to 53 players, the Rams on Sunday continued to tweak, claiming three players off waivers, releasing three players and assigning all but one spot on the 10-player practice squad.

The roster could be revised before Sunday’s game at the Coliseum, most notably if star defensive lineman Aaron Donald reports this week, with or without a new contract.

The Rams, by virtue of their 4-12 record last season, were fifth in the waiver-wire selection order.

They claimed and were assigned defensive lineman Quinton Jefferson and centers Aaron Neary and J.J. Dielman.

Jefferson, who played in college at Maryland, was a fifth-round pick by the Seattle Seahawks last year. He played in three games before suffering a season-ending knee injury.

Dielman, who also played tackle for two seasons at Utah, was a fifth-round pick by the Cincinnati Bengals in this year’s draft.

Neary played at Eastern Washington and was on the Philadelphia Eagles practice squad last season.

To make room on the roster, the Rams waived linebacker Nic Grigsby, tight end Johnny Mundt, and defensive lineman Louis Trinca-Pasat.

Four players waived by the Rams on Saturday — linebacker Kevin Davis, linebacker Josh Forrest, receiver Nelson Spruce and running back Lenard Tillery — cleared waivers and were put on injured reserve by the Rams.

Nine players were assigned to the practice squad: receiver Paul McRoberts, fullback Sam Rogers, tight end Travis Wilson, offensive linemen Jake Eldrenkamp and Michael Dunn, defensive lineman Omarius Bryant, linebackers Carlos Thompson and Cassanova McKinzy, and defensive back Isaiah Johnson.

Donald’s status for the opener remained in limbo Sunday, a day off for players.

Coach Sean McVay said Saturday that he remained optimistic that Donald would report in time to play in the opener, but that other players would be prepared if he does not.

Ethan Westbrooks and rookie Tanzel Smart are among those who could be part of a defensive line rotation if Donald continues his holdout.

“Certainly, we know the type of player that Aaron is,” McVay said Saturday, “but I think credit to the players right now that are here.

“They won’t allow it to be a distraction, and if he does come back, everybody will welcome him back with open arms and be happy to have him.”

Four other players who sat out all preseason games are expected to practice this week and play in the opener.

Linebackers Robert Quinn and Mark Barron, and cornerback Kayvon Webster participated in a light workout Saturday that was closed to the media, McVay said.

Receiver Tavon Austin, sidelined during the preseason because of a hamstring injury, was a full-speed participant in a pregame workout with other skill players at Green Bay on Thursday.

“He looks explosive and he looks like the Tavon Austin that we’re accustomed to seeing,” McVay said.

Robert Woods, Sammy Watkins and Cooper Kupp are the starting receivers, but Austin is expected to play a role as a wideout and out of the backfield. He also will return punts.

“Having a guy like that, especially with the energy that he brings and everything that comes along with him is really important for our team,” quarterback Jared Goff said last week. “I had a good talk with him about ways we would love to use him. I’m not coaching by any means, but we’d love to get him out there and hopefully get some plays with him involved.”

Austin signed a four-year, $42-million extension before the 2016 season. The fifth-year pro knows he will be a big part of the offense, Goff said.

“He knows how much we’re going to need him,” Goff said, “and how much he’s going to make a difference.”

gary.klein@latimes.com

Follow Gary Klein on Twitter @latimesklein