The light at the end of the tunnel is beginning to shine on the long list of injured Cubs players.

Anthony Rizzo returned to the lineup Tuesday night against the Padres after missing the previous 6 games with back tightness. He collected hits in his first 2 trips to the plate against San Diego starter Ryan Weathers.

He was petitioning manager David Ross for an at-bat Monday afternoon and has been feeling good over the last couple days. He initially tweaked his back slipping out of the batter’s box against the Nationals on the last homestand.

The Cubs have been understandably cautious with Rizzo’s health, especially given his history of minor back issues. They’ll continue to monitor him but Ross feels comfortable with letting his All-Star first baseman loose right now.

“As long as he’s healthy and feeling good, we’ll listen to that and let him play,” Ross said. “If there’s days where he’s barking, he’ll come in and talk to me. Or if I see body language where it feels like he can’t bend down and get ground balls or get off his ‘A’ swing, then we’ll monitor that accordingly.

“Once I put him in the lineup, I feel free that they’re able to play until they tell me they’re not. With the back stuff, if it does flare up, that’s a day-to-day basis thing.”

Meanwhile, the Cubs are sending Jason Heyward and Jake Marisnick on a rehab assignment. The veteran outfielders are recovering from hamstring injuries and expected to meet up with Triple-A Iowa during their series in Omaha.

If all goes well, the Cubs are hoping to have Heyward and Marisnick rejoin the team in San Francisco. The Cubs begin a 4-game series with the Giants Thursday night.

Marisnick last played May 9, when he left in the 1st inning of the Cubs’ game against the Pirates. Heyward joined him on the shelf 10 days later.

Rookie reliever Justin Steele is also recovering from a hamstring strain and threw a 10-pitch light bullpen off the mound this week and reported feeling great afterward.

Nico Hoerner is a week out from his own hamstring strain but the Cubs got good news on the status of their young infielder.

“Things are progressing well on Nico,” Ross said. “He had a good day [Monday].”

Matt Duffy (low back) is eligible to return from the IL this week but he just started doing baseball activities. He last played May 22 and was placed on the IL May 25 (retroactive to May 23).

Duffy took some light swings off a tee Monday but has not yet resumed running or fielding ground balls so he will be on the shelf a little while longer.