On Wednesday, San Francisco 49ers general manager John Lynch had an opportunity to address the trade of tight end Vance McDonald to the Pittsburgh Steelers, stating that the deal came down to fit and the depth already at the position. As a result of the trade, the 49ers moved up in next year's draft from the fifth round to the fourth.

On Thursday, prior to the 49ers' preseason finale against the Los Angeles Chargers, head coach Kyle Shanahan had an opportunity to explain the trade via a conversation on KNBR.

"It's really just in how do you think you can make your team better," Shanahan explained. "We were happy with our draft pick in (George) Kittle. He's done a real good job for us. Vance has gotten better since he's been here too. Even talking to Vance before he left that Vance had made a believer in me. He really worked at the things we asked him to do. Started off a little rusty in our run game and things like that but the things I asked him to do, he was more than willing. He got better because of it.

"So, he didn't make it easy for us but when Pittsburgh came around, we thought we could improve our team going forward without really taking a step back. That's something that we thought was important to do for us."

You can listen to the entire interview with Shanahan below.

Lynch also identified rookie tight end George Kittle's progress as one of the reasons that the 49ers felt comfortable moving on from McDonald. The general manager said Kittle is fast, blocks well, and has the ability to separate from defenders.

"We're just extremely high on him," Lynch said on Wednesday. "He's shown that he can be an all-around tight end."

Last December, McDonald and the 49ers' previous regime agreed to a five-year, $35 million extension that included $16 million guaranteed. McDonald ended the 2016 season on injured reserve.

Prior to the injury, McDonald was having the best season of his career. He had 391 yards receiving, which was a career best, and four touchdowns last season. He was originally selected by the 49ers in the second round of the 2013 NFL Draft out of Rice. In four seasons with the 49ers, he appeared in 48 games, started 30, and registered 64 receptions for 866 yards and seven touchdowns.

"It's tough to look at your owner, who just gave Vance a big deal last year and say, 'Hey, we feel like we're going to move in a different direction,'" Lynch said, "because he just was paid a bunch of money. But that's also understood that when new regimes come in, they're going to see things differently and we saw the best fit for our organization was to do something."