The 49ers are still looking to add to their defensive line. After signing former first-round pick Glenn Dorsey in the first week of free agency, San Francisco has rumored interest in former Chicago Bears defensive lineman Israel Idonije.

Idonije, 32, went undrafted in the 2003 draft before being signed as an undrafted free agent by the Cleveland Browns. He was released from their practice squad and later picked up by the Chicago Bears, who he’s been with ever since.

After a solid career with Chicago as a versatile defensive lineman and special teams player he has slipped into free agency. His last season was impressive — Idonije accumulated 48 tackles and 7.5 sacks, starting out at defensive end before moving to defensive tackle in the latter part of the season. Of course, Idonije has been playing in the Bears 4-3 defensive scheme, so things would change if he and the 49ers do eventually strike a deal.

Another note that might interest the 49ers — Idonije has blocked eight kicks (field goals plus extra points) in his career.

According to Jeff Deeney of Pro Football Focus, Idonije was ranked 9th out of 43 4-3 defensive ends in terms of pass rush productivity in 2012. He had a +17.5 overall rating last year. The only available free agent better is John Abraham, who visited the 49ers two weeks ago and left without a deal.

PFF has Idonije ranked +7.5 in run defense and +10.5 in pass rush with 55 quarterback pressures. His most impressive performance of the season was a three-sack performance against the St. Louis Rams in Week 3, but some of his highest marks came in Week 12 against the Minnesota Vikings (+5.5 pass rush rating with one sack, one QB hit and five hurries) and the next week against the Seattle Seahawks (+3.1 pass rush rating with 1 QB hit and six hurries), after he moved to the interior of the Bears’ defensive line.

Idonije is one of the best defensive linemen left on the market and he’s certainly posted higher marks than the options I suggested a couple weeks ago. With such high productivity the obvious question is what his asking price will be, but with the second week of free agency quickly coming to a close and little interest coming his way, Idonije may not be able to name his price.

He would be a welcome addition to the 49ers defense, especially because of his versatility and his balanced run-stopping and pass-rushing abilities. Abraham, for example, posted an insane +20.4 grade in pass rush, but he was -0.8 against the run. The 49ers want a player who can contain running backs while still making lives miserable for opposing quarterbacks. They also want to add players capable of being platooned and playing in a variety of positions depending on defensive formations. Idonije fits the mold perfectly, so this one is a signing that would seem to make perfect sense.