Tim Tebow not ruled out by Belichick, could door still be open?

Could the door be open for quarterback Tim Tebow to return to the New England Patriots?

Patriots coach Bill Belichick on Monday declined to rule out bringing back the popular but underperforming quarterback some time this season, noting that it's not uncommon for him to re-sign a player he's already cut.

"I don't know what's going to happen during the year, but certainly we've had a lot of players who've left here and come back here," Belichick told reporters in his first comments since releasing Tebow on Saturday. "That's already happened multiple times this year."

The Patriots have only two quarterbacks on the active roster. If starter Tom Brady or backup Ryan Mallett is injured, they would need another.

The decision to go with two quarterbacks, as the team has done in the past, was "'cause we thought it was the best thing for the team."

Tebow was released Saturday when NFL teams were required to cut their rosters to 53 players. The 2007 Heisman Trophy winner was 11 for 30 for 145 yards with two touchdowns and two interceptions in three exhibition games.

The Patriots commonly bring back players after releasing them. In fact, on Monday they re-signed cornerback Marquice Cole just one day after releasing him.

"There are a million things that go into every decision, personnel decision," Belichick said. "There are a lot of things that play off one another. In the end, we did what we thought was best for the team, at every position, every one."

Also Monday, Belichick said tight end Rob Gronkowski is "definitely moving forward" after an offseason of surgeries. Belichick would not elaborate on the future for the two-time Pro Bowl selection, who practiced in full pads Sunday for the first time since having back surgery, taking part in drills with his teammates during the 15 minutes reporters were allowed to observe the start of practice.

"This is his first opportunity to be in pads," Belichick said. "So, yes, he's definitely moving forward."

Gronkowski, who was back on the field on Monday, has had four operations this year, three on his broken left forearm and one on his back; he also had forearm surgery last year after breaking it on Nov. 18 while blocking on an extra point against the Indianapolis Colts. Gronkowski isn't expected to ready for the opener, but Belichick decided not to place him on the physically unable to perform list, which would have required him to miss at least the first six games of the season.

Belichick repeatedly declined to elaborate on Gronkowski's timetable.

"We take it day to day," the coach said. "Evaluate tomorrow based on how today goes, see how it goes. See how tomorrow goes and deal with whatever that day is, Wednesday or Thursday or whatever the day is. We'll take it day to day. It's the same way we do with everybody."

Gronkowski has caught 187 passes for 38 touchdowns in three NFL seasons despite missing the last five regular-season games in 2012. Last year's other star tight end, Aaron Hernandez, is being held without bail on a murder charge.

Cole, released on Sunday, has played four seasons with the New York Jets and Patriots. He played in 14 games last year in New England and finished with 12 tackles, one interception, three passes defensed and seven special teams tackles.

The Patriots also released offensive lineman Josh Kline on Monday and re-signed rookie WR Quentin Sims to the practice squad. Sims joined the Patriots as a rookie free agent and was cut on Aug. 31.